Updated/Added build instructions for OS/2.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@5937 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/gtk/install.txt

@@ -154,7 +154,7 @@ to Andrea Venturoli <a.ventu@flashnet.it> and patches to
 the wxWindows mailing list.
 
 You'll need OS/2 Warp (4.00FP#6), X-Free86/2 (3.3.3 or newer), 
-GTK+ (1.2.1 or newer), emx (0.9d fix 1), flex (2.5.4), yacc (1.8), 
+GTK+ (1.2.5 or newer), emx (0.9d fix 1), flex (2.5.4), yacc (1.8), 
 korn shell (5.2.13), Autoconf (2.13),  GNU file utilities (3.6), 
 GNU text utilities (1.3), GNU shell utilites (1.12), m4 (1.4), 
 sed (2.05), grep (2.0), Awk (3.0.3), GNU Make (3.76.1).
@@ -169,10 +169,20 @@ SET COMSPEC=sh
 
 Notice you can choose whatever you want, if you don't like OS2X.
 
-After running configure, you'll have to apply to modifications manually
-to the created Makefile:
-- Replace all ":" with ";" in the VPATH variable
-- Replace "ley.yy.c" with "lexyy.c"
+Now, run autoconf in the main directory and in the samples, demos
+and utils subdirectory. This will generate the OS/2 specific
+versions of the configure scripts. Now run
+    configure --with-gtk
+as described above.
+
+If you have pthreads library installed, but have a gtk version
+which does not yet support threading, you need to explicitly
+diable threading by using the option --disable-threads.
+
+Note that configure assumes your flex will generate files named
+"lexyy.c", not "lex.yy.c". If you have a version which does
+generate "lex.yy.c", you need to manually change the generated
+makefile.
 
 * Building wxGTK on SGI
 --------------------------