xbps 0.3

This version contains changes developped in almost 2 months. Some highlighted features include:

* Remote repositories support. HTTP/HTTPS/FTP repositories are supported.
* Improved required version matching.
   See https://blueprints.launchpad.net/xbps/+spec/improved-version-matching
   for more information.
* xbps-src code has been removed, and now it's not shipped anymore.
   xbps-src is available from the GIT repository at http://repo.or.cz/w/xbps.git
* Upgrades of essential packages have been improved, and now it will look for obsolete
   files between current and new version to be installed, thus removing obsolete files
   automagically.
* Added manual pages for xbps-bin(8) and xbps-repo(8) commands.
* xbps-repo(8):
   Added new targets: sync, show-deps, show-files.
   Improved the search target, now it can accept shell style patterns.
   Improved the genindex target, it's now 60% faster.
   Created static binary.
* xbps-bin(8):
   Added new targets: check, show-revdeps.
   Improved the install, update and autoupdate targets, they are now 35% faster.
   Created static binary.
* xbps-uhelper: new command that replaces xbps-cmpver, xbps-digest, xbps-pkgdb.
* Package INSTALL/REMOVE scripts are unpacked with 0750 permissions.
* All code the is built with -fstack-protector, rewritten Makefiles allowing parallel builds.