Add .pp to the list of extensions for Pascal source files.

Index: source/preferences.c
--- source/preferences.c.orig
+++ source/preferences.c
@@ -759,7 +759,7 @@ static PrefDescripRec PrefDescrip[] = {
         Makefile:MAKEFILE:::None:8:8::\n\
         Matlab:.M .OCT .SCI:::::::\n\
         NEdit Macro:.NM .NEDITMACRO:::::::\n\
-        Pascal:.PAS .P .INT:::::::\n\
+        Pascal:.PAS .P .PP .INT:::::::\n\
         Perl:.PL .PM .P5:\"^[ \\t]*#[ \\t]*!.*perl\":Auto:None:::\".,/\\\\`'!$@#%^&*()-=+{}[]\"\":;<>?~|\":\n\
         PostScript:.ps .PS .eps .EPS .epsf .epsi:\"^%!\":::::\"/%(){}[]<>\":\n\
         Python:.PY:\"^#!.*python\":Auto:None:::\"!\"\"#$%&'()*+,-./:;<=>?@[\\\\]^`{|}~\":\n\
@@ -788,7 +788,7 @@ static PrefDescripRec PrefDescrip[] = {
         Makefile:Makefile makefile .gmk:::None:8:8::\n\
         Matlab:.m .oct .sci:::::::\n\
         NEdit Macro:.nm .neditmacro:::::::\n\
-        Pascal:.pas .p .int:::::::\n\
+        Pascal:.pas .p .pp .int:::::::\n\
         Perl:.pl .pm .p5 .PL:\"^[ \\t]*#[ \\t]*!.*perl\":Auto:None:::\".,/\\\\`'!$@#%^&*()-=+{}[]\"\":;<>?~|\":\n\
         PostScript:.ps .eps .epsf .epsi:\"^%!\":::::\"/%(){}[]<>\":\n\
         Python:.py:\"^#!.*python\":Auto:None:::\"!\"\"#$%&'()*+,-./:;<=>?@[\\\\]^`{|}~\":\n\
