Refactoring and implementing package.go

The file package.go does a lot to make the rest of the implementation of
the functionality very simple. It is also much more reliable, as the
packages are properly inspected, instead of just relying on regular
expressions as I did in the past. Further, the actions have been
consolidated into the actions.go file.
Refactoring and bugfixes

Now repoctl can list all the packages in a repository.
Adding proper GetAllPackages to support multi matching
Ignoring repoctl binary
Completing Update() function and draft of Add()
Adding FastUpdate option
Adding SearchAUR function stub
Rudimentary framework and functionality
Implementing command line arguments and basic update and add
Updating TODO
Removing unneeded util file
Preparing package.go for further modification

The next step will probably be to split package.go out into a
new package.
Bugfix: update for current goulash/pr package
Moving pacman related code to goulash/pacman
Restructuring repoctl

Adding status and removing sync actions.
Changing command line option set.
Fix Status() with new ConcurrentlyReadAUR function from pacman
Implemented List and Status in parallel fashion

Moved all utility functions into util.go.
First draft of Update, Add, Remove

And changed options a little to make sense. This commit compiles.
Restructuring Config to avoid constantly joining path and database
Adding preliminary PKGBUILD