Qt4 autoconf cleanup.

Qt4 autoconf cleanup.

	* config/qt4.m4
	(QT4_FIND_PATH, QT_FIND_UIC4, QT_FIND_MOC4): remove,
	AC_PATH_PROGS does this very well.
	(QT4_DO_PKG_CONFIG): add $QT4DIR/lib to pkg-config search path;
	do not run QT4_DO_MANUAL_CONFIG on failure.
	(QT4_DO_MANUAL_CONFIG): remove some code.
	(QT4_DO_IT_ALL): move code to handle --with-foo here; move
	code to search for moc/uic here; call QT4_DO_PKG_CONFIG first,
	and QT4_DO_MANUAL_CONFIG on failure.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@14829 a592a061-630c-0410-9148-cb99ea01b6c8