Consolidate plugin regex into core.

Delete metadata/regex.xml.in, plugins/regex.c.
Remove regex from metadata/Makefile.am, plugins/Makefile.am.
Remove regex from metadata/core.xml.in, metadata/fade.xml.in.
Remove regex from po/POTFILES.in

include/fusilli-core.h:
	Bump CORE_ABIVERSION

	Add roleAtom, visibleNameAtom in CompDisplay
	                     (moved from RegexDisplay)

	Add title, role in CompWindow (moved from RegexDisplay)

	Add function prototypes for:
		getWindowStringProperty (was regexGetStringProperty)
		getWindowTitle (was regexGetWindowTitle)

	Remove matchInitExp, matchExpHandlerChanged from CompDisplay

Remove matchExpHandlerChanged from plugins/blur.c, plugins/fade.c,
                                   plugins/obs.c

src/event.c: Consolidate regexHandleEvent into handleEvent.

src/display.c: Initialize roleAtom, visibleNameAtom
               Remove matchInitExp, matchExpHandleChanged.

src/window.c: Definitions for getWindowStringProperty, getWindowTitle.
              Initialize and free w->title, w->role.

src/match.c:
	Add header <regex.h>
	Add regexMatchExpInit, regexMatchExpFini
	Add regexMatchExpEvalTitle, regexMatchExpEvalRole,
	    regexMatchExpEvalClass, regexMatchExpEvalName
	Modify matchInitExp
	Remove matchExpHandlerChanged