Redo the BUILD_MAP code to not depend on libunicode. Now it only generates

Redo the BUILD_MAP code to not depend on libunicode. Now it only generates

	* camel-charset-map.c: Redo the BUILD_MAP code to not depend on
	libunicode. Now it only generates a map of "popular" 8bit
	encodings. (It's not worthwhile to support obscure encodings,
	because any mailer that supports them will support UTF8 too. And
	Chinese and Japanese use mostly the same UTF8 characters so you
	need to decide between those encodings based on the locale or
	the charset of the message you're replying to or the input
	method you used. So this is sufficient for camel_charset_best's
	use.)

	* camel-charset-map-private.h: Regenerated.

	* camel.c (camel_shutdown): Move #ifdefs around to prevent a
	warning.