maint: Rename regexp.h to lo-regexp.h, regexp.cc to lo-regexp.cc in liboctave. Remove namespace hit with regexp.cc in libinterp/corefcn. * liboctave/util/lo-regexp.cc: Renamed from regexp.cc. * liboctave/util/lo-regexp.h: Renamed from regexp.h. * liboctave/util/module.mk: Add files to build system. * libinterp/corefcn/regexp.cc, libinterp/corefcn/symtab.h, libinterp/corefcn/variables.cc: Update #include stmts to new name.

--- a/libinterp/corefcn/regexp.cc	Tue Jul 09 16:08:16 2013 -0700
+++ b/libinterp/corefcn/regexp.cc	Tue Jul 09 16:47:57 2013 -0700
@@ -33,7 +33,7 @@
 #include "base-list.h"
 #include "oct-locbuf.h"
 #include "quit.h"
-#include "regexp.h"
+#include "lo-regexp.h"
 #include "str-vec.h"
 
 #include "defun.h"