Support xz and lzma decompression via liblzma

	Support xz and lzma decompression via liblzma
	* Makefile.am: Add -DLZMA_API_STATIC to AM_CPPFLAGS,
	-lzma to setup_LDADD, and -static-libtool-libs to
	setup_LDFLAGS. Update setup_SOURCES.
	* compress.cc: Update includes.
	(compress::decompress): Use compress_xz rather than
	compress_lzma; compress_xz supports both xz and lzma
	decompression.
	* compress_xz.h: New.
	* compress_xz.cc: New.
	* compress_lzma.h: Removed.
	* compress_lzma.cc: Removed.
	* lzma-sdk/LzmaDec.c: Removed.
	* lzma-sdk/LzmaDec.h: Removed.
	* lzma-sdk/Types.h: Removed.