Bug 1093191 part 1: Remove some unnecessary #includes of stdio.h "for printf" in some libeditor files that don't use printf. r=ehsan
Bug 1093191 part 2: Add some missing includes & forward-decls in libeditor .h files. r=ehsan
Bug 1093191 part 3: Make .cpp files in libeditor #include their own .h file first. r=ehsan