Static files are now under a directory in xdg directories (config or cache)

New paths:
$XDG_CONFIG/packages.conf
$XDG_CONFIG/sendmail.conf
$XDG_CACHE/packages.conf

Doesn't compare versions, let that to new mode

Archversion now use a new cache format which store upstream and downstream
ersions (with timestamp)

cache is updated by calling the sync command

This option allow to use a regex to exclude upstream versions before trying to
find the last one. Useful to exclude rc* version from a list without building
a complex regex_version.

Previously update mode never call upstream check function and only use cached
data.

Now it always call upstream check and only save it if -S is omitted

To keep the rules of using binary name of the package in the config file,
we grab the pkgname[0] of the bash array. This is done to stay compatible with
archweb.

As bash 4.2.x doesn't export array to env (well know bug). We add a custom
export as string the first field of pkgname array as pkgname0.

pacman database queries are now handled by a singleton class into pacman module.
This will avoid a huge memory consumption to the current implementation.

Allow upstream web parsing to be retryed in case of error. The number of retry
can be set with the retry parameter.

This command allow archversion to quickly update package to its last upstream
version.

Our error exceptions are now catched globablly and __str__ method describe
the issue

- rename config example files
- remove __init__.py from /usr/bin
- install README.rst and example*.conf in doc directory
- ship misc file into dist tarball

Allow to check package against local pacman synced db

Add new deps to alpm

Instead of using LooseVersion from distutils (a missed deps btw), I switched to
a custom version not directly based on tuples comparaison. Because it doesn't
support different type inside tuple.

All my package are currently passing better than with LooseVersion.

We also doesn't compute the full sorted list of versions but only the max, which
is the last.

This will avoid to run make every time a fix is provided in archversion (dev only)

I guess I missed to finished moving BaseConfigFile class to a child class
of OrderedDict instead of havind a method config.