tweaks: drop obsolete 'nano.spec' from .gitignore file, and reshuffle

.gitignore

@@ -13,6 +13,9 @@ core
 .gdb_history
 .gdbinit
 
+/src/nano
+/src/revision.h
+
 /ABOUT-NLS
 /INSTALL
 /aclocal.m4
@@ -35,7 +38,7 @@ core
 /mkinstalldirs
 /stamp-h1
 
-# gettext m4 files.
+# Gettext m4 files:
 /m4/codeset.m4
 /m4/extern-inline.m4
 /m4/fcntl-o.m4
@@ -69,13 +72,9 @@ core
 /m4/wint_t.m4
 /m4/xsize.m4
 
-# gnulib entries
+# Gnulib stuff:
 /gnulib/
 /lib/
 /m4/.gitignore
 /m4/gnulib-cache.m4
 /snippet/
-
-/nano.spec
-/src/nano
-/src/revision.h