Add write support for Fgdb layers and make it possible to remove a prefix from the expressions. The expressions returned by arcgis for Fgdb data contain the data source name as a prefix. Mapserver does not need it and does not match those expressions so they have to be removed

SYMBOL
	NAME "l_dashed_1pt_c255-255-255"
	TYPE SIMPLE

	#dashed line where the dashes and spaces are both five pixels long
	#first number: dash length 
	#second number: space length
	PATTERN 5 5 END 
END