Refactor regex and implement UTF8 mode for GRegex

- with non-unicode byte to Private Use Area A mapping
- move all ifdefs to iregex.h file only

src/fe-common/core/hilight-text.h

@@ -1,10 +1,7 @@
 #ifndef __HILIGHT_TEXT_H
 #define __HILIGHT_TEXT_H
 
-#ifndef USE_GREGEX
-#  include <regex.h>
-#endif
-
+#include "iregex.h"
 #include "formats.h"
 
 struct _HILIGHT_REC {
@@ -24,12 +21,7 @@ struct _HILIGHT_REC {
 	unsigned int fullword:1; /* match `text' only for full words */
 	unsigned int regexp:1; /* `text' is a regular expression */
 	unsigned int case_sensitive:1;/* `text' must match case */
-#ifdef USE_GREGEX
-	GRegex *preg;
-#else
-	unsigned int regexp_compiled:1; /* should always be TRUE, unless regexp is invalid */
-	regex_t preg;
-#endif
+	Regex *preg;
 	char *servertag;
 };