Various warning/header cleanups necessary for clean gcc 4.3 build.

	Various warning/header cleanups necessary for clean gcc 4.3 build.
	* ConnectionSetting.cc: Include stdlib.h.
	* LogFile.cc: Ditto.
	* Makefile.am: Don't hardcode paths to MinGW libz and libbz2.
	* PickView.cc: Include limits.h.
	* String++.cc: Include string.h.
	* archive_tar.cc (archive_tar::next_file_name): Silence nested-if
	warning.
	* autoload.c: Switch back to .text section before emiting
	autoload_common.
	* choose.cc: Include stdlib.h and algorithm.
	* compress_gz.cc: Include memory.h and malloc.h.
	* filemanip.cc: Include string.h.
	(parse_filename): Silence nested-if warning.
	* nio-ftp.cc (NetIO_FTP::NetIO_FTP): Silence warning.
	* package_db.cc: Include algorithm.
	* site.cc (get_site_list): Silence warning.
	* win32.cc: Include memory.
	* csu_util/MD5Sum.cc: Include string.h.
	* CHANGES: Update.