This commit is a complete rebuild of pkictl. Before everything was all
over the place and adding new commands was kind of a hassle.
Now each command has its own file and can be adjusted on a command
basis. Options are still used by the same name, but can now use
different descriptions.
This is a major rebuilding of the CLI. The library part is split out
into pkilib and the cli handles only the communication with the user,
I/O and the library.
The API will still look the same, but the code should be much better to
grasp. Instead of repeating everything, more will be grouped together
and reused.