xbps: some implemented features for 0.4

[Juan RP]

Hi,

I've just implemented the blueprint 'install-pkg-by-pkgmatch'
as specified in:

https://blueprints.launchpad.net/xbps/+spec/install-pkg-by-pkgmatch

That means that you can now do the following (please note that these
are some basic examples, the pkgmatch code is able to do a lot more!):

$ xbps-bin install 'bash>=4.0<4.1'
$ xbps-bin install coreutils-5.1
$ xbps-bin install 'kernel==2.6.32.[45]'

Don't forget that you have to quote the pattern, otherwise the shell
will think it's a redirection or a shell expression!

Some time ago I also implemented support to be able to specify multiple
package arguments to the xbps-bin(8) and xbps-repo(8) commands, as
specified in:

https://blueprints.launchpad.net/xbps/+spec/arbitrary-pkgname-args

That means that with these two blueprints implemented you can mix
both features like:

$ xbps-bin install bash 'coreutils>=5.0' 'kernel>=2.6.32.1<2.6.32.4'

This code will appear in the next 0.4 version, it's planned to
be released in 2 weeks approximately.

Enjoy.