Fix detection of FTGL in configure.in

Also modify installed headers to search for FTGL headers in
the right directory.  This is not needed to build opencascade,
but may help people including those headers.
And last, fix usage of FTGL, FTFace is an internal structure
of FTGL and is no more exported.

Index: opencascade/ros/configure.in
===================================================================
--- opencascade.orig/ros/configure.in
+++ opencascade/ros/configure.in
@@ -422,7 +422,7 @@
   HAVE_FTGL=yes
   HAVE_FTGL_INC=yes
   CPPFLAGS="-I$ftgl/include $CPPFLAGS";
-  AC_CHECK_HEADER( [FTGL/FTGL.h], [], [HAVE_FTGL_INC=no] )
+  AC_CHECK_HEADER( [FTGL/ftgl.h], [], [HAVE_FTGL_INC=no] )
   if test "x$HAVE_FTGL_INC" = "xyes"; then
     CSF_FTGL_INCLUDES="-I$ftgl/include/FTGL"
     HAVE_FTGL_LIB=yes
@@ -431,9 +431,9 @@
     LIBS_sv=$LIBS
     LIBS="-lftgl $CSF_OpenGlLibs_LIB $LIBS"
     #we have problem with unresolved symbols on 64 stations
-    CSF_FTGL_LIB="-L$ftgl/lib -lftgl"
+    CSF_FTGL_LIB="-L$ftgl/lib -lftgl -lfreetype"
     AC_TRY_LINK([
-#include <FTGL/FTGL.h>
+#include <FTGL/ftgl.h>
 #include <FTGL/FTGLTextureFont.h>
 ], [
 FTGLTextureFont font("");], [
Index: opencascade/ros/inc/OpenGl_FontMgr.hxx
===================================================================
--- opencascade.orig/ros/inc/OpenGl_FontMgr.hxx
+++ opencascade/ros/inc/OpenGl_FontMgr.hxx
@@ -7,7 +7,7 @@
 # include <stdlib.h>
 #endif
 
-#include <FTFont.h>
+#include <FTGL/FTFont.h>
 
 #include <InterfaceGraphic.hxx>
 #include <TCollection_HAsciiString.hxx>
Index: opencascade/ros/inc/OpenGl_TextRender.hxx
===================================================================
--- opencascade.orig/ros/inc/OpenGl_TextRender.hxx
+++ opencascade/ros/inc/OpenGl_TextRender.hxx
@@ -5,7 +5,7 @@
 #include <NCollection_DataMap.hxx>
 #include <TCollection_AsciiString.hxx>
 #include <TCollection_HAsciiString.hxx>
-#include <FTFont.h>
+#include <FTGL/FTFont.h>
 
 #define NUM_FONT_SIZES 40
 #define NUM_CHAR_FONT 1024
Index: opencascade/ros/src/OpenGl/OpenGl_FontMgr.cxx
===================================================================
--- opencascade.orig/ros/src/OpenGl/OpenGl_FontMgr.cxx
+++ opencascade/ros/src/OpenGl/OpenGl_FontMgr.cxx
@@ -1,8 +1,6 @@
 #include <OpenGl_FontMgr.hxx>
 
-#include <FTGLTextureFont.h>        
-#include <FTLibrary.h>
-#include <FTFace.h>
+#include <FTGL/ftgl.h>
 #include <Standard_Stream.hxx>
 
 #undef TRACE
@@ -60,6 +58,8 @@
 void OpenGl_FontMgr::_initializeFontDB()
 {
   Handle(OSD_FontMgr) fntMgr = OSD_FontMgr::GetInstance();
+  FT_Library  library;
+  int error = FT_Init_FreeType( &library );
   if ( !fntMgr.IsNull() ) {
 
     OSD_NListOfSystemFont fontList = fntMgr->GetAvalableFonts();
@@ -68,13 +68,14 @@
       OSD_NListOfSystemFont::Iterator it(fontList);
       for ( ; it.More(); it.Next() ) {
         OGLFont_SysInfo* info = new OGLFont_SysInfo();
-        if ( it.Value()->FontAspect() == OSD_FA_Regular ) {
+        if ( it.Value()->FontAspect() == OSD_FA_Regular && !error ) {
           //this workaround for fonts with names dependent on system locale.
           //for example: "Times New Roman Fett Kursive" or "Times New Roman Gras Italiqui"
-          FTFace face(it.Value()->FontPath()->ToCString());
-              
-          if ( face.Error() == FT_Err_Ok ) {
-            if ( (*face.Face())->style_flags == 0 ) {
+          FT_Face ftFace;
+          error = FT_New_Face(library,
+              it.Value()->FontPath()->ToCString(), 0, &ftFace);
+          if ( !error ) {
+            if ( ftFace->style_flags == 0 ) {
               info->SysFont = it.Value();
             }
             else {
@@ -82,27 +83,30 @@
 #ifdef TRACE
               cout << "TKOpenGl::initializeFontDB() detected new font!\n"
                 << "\tFont Previous Name: " << it.Value()->FontName()->ToCString() << endl
-                << "\tFont New Name: " << (*face.Face())->family_name << endl
-                << "\tFont Aspect: " << (*face.Face())->style_flags << endl;
+                << "\tFont New Name: " << ftFace->family_name << endl
+                << "\tFont Aspect: " << ftFace->style_flags << endl;
 #endif
               OSD_FontAspect aspect = OSD_FA_Regular;
-              if ( (*face.Face())->style_flags == (FT_STYLE_FLAG_ITALIC | FT_STYLE_FLAG_BOLD) )
+              if ( ftFace->style_flags == (FT_STYLE_FLAG_ITALIC | FT_STYLE_FLAG_BOLD) )
                 aspect = OSD_FA_BoldItalic;
-              else if ( (*face.Face())->style_flags == FT_STYLE_FLAG_ITALIC )
+              else if ( ftFace->style_flags == FT_STYLE_FLAG_ITALIC )
                 aspect = OSD_FA_Italic;
-              else if ( (*face.Face())->style_flags == FT_STYLE_FLAG_BOLD )
+              else if ( ftFace->style_flags == FT_STYLE_FLAG_BOLD )
                 aspect = OSD_FA_Bold;
 
 #ifdef TRACE
               cout << "\tOSD_FontAspect: " << aspect << endl;
 #endif
               Handle(TCollection_HAsciiString) aFontName =
-                new TCollection_HAsciiString( (*face.Face())->family_name );
+                new TCollection_HAsciiString( ftFace->family_name );
               info->SysFont = new OSD_SystemFont( aFontName, aspect, it.Value()->FontPath() );
             }
           }
           else
+          {
+            error = 0;
             continue;
+          }
         } else {
           info->SysFont = it.Value();
         }