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/core/ignore.h

@@ -1,9 +1,7 @@
 #ifndef __IGNORE_H
 #define __IGNORE_H
 
-#ifndef USE_GREGEX
-#  include <regex.h>
-#endif
+#include "iregex.h"
 
 typedef struct _IGNORE_REC IGNORE_REC;
 
@@ -20,12 +18,7 @@ struct _IGNORE_REC {
 	unsigned int regexp:1;
 	unsigned int fullword:1;
 	unsigned int replies:1; /* ignore replies to nick in channel */
-#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;
 };
 
 extern GSList *ignores;