xbps 0.4

 * libxbps, xbps-bin(8), xbps-repo(8): redirect all warning and error
   messages to stderr.

 * libxbps: changes xbps_yesno() and xbps_noyes() to only accept "yes" or "no"
   (case insensitive) answers rather than 'y' or 'n', to avoid mistaken answers.

 * xbps-repo(8): added support to the 'search' target to find exact matches,
   i.e 'xbps-repo search bash'.

 * xbps-bin(8) added support to the 'install', 'remove' and 'update'
   targets to accept any arbitrary number of package names, i.e
   "xbps-bin install foo blah baz".
   See https://blueprints.launchpad.net/xbps/+spec/arbitrary-pkgname-args

 * xbps-bin(8): added support to the 'install' and 'update' targets to
   accept package patterns, i.e "xbps-bin install 'foo<=3.0'.
   See https://blueprints.launchpad.net/xbps/+spec/install-pkg-by-pkgmatch

 * libxbps: fixed some bugs while upgrading essential packages when new package
   didn't have an INSTALL or REMOVE script and old package had them.

 * libxbps: fixed some memleaks found by cppcheck and valgrind.

 * Makefiles reworked to support parallel builds.

 * libxbps: many exported functions to the API are now internal and not
   exported, because they were only used internally. The API is still not
   finished and may be changed without notice.

 * libxbps: be more strict finding required metadata plist files in binary
   packages. Now the code checks for the two required plist files to be at
   index <= 4 and doesn't write any entry to storage until they aren't found.

 * Added doxygen documentation for the API, enabled with BUILD_API_DOCS.

 * libxbps: synced libfetch code with NetBSD's pkgsrc, updated to 2.30.

 * xbps-bin(8): when downloading binary packages, it now sets default
   libfetch cache connection limits, thus reusing connections to the same host.

 * xbps-uhelper: the 'fetch' target now accepts an arbitrary number of
   arguments, and sets default libfetch cache connection limits.

 * xbps-bin(8): enable -f option for the 'purge' and 'remove' targets.
   If set, files will be removed even if its hash doesn't match for the
   'remove' target, and configuration files for the 'purge' target.

 * libxbps: if updating a package, always overwrite files while unpacking;
   compare old and new files to remove obsoletes if necessary. This makes
   the "essential" object in package dictionary unnecessary, because all
   packages are treated as they were essential.