Kupfer's git master is more interesting and more unstable

[Ulrik Sverdrup <ulrik sverdrup gmail com>]

Hello all,

There are some interesting changes in Kupfer's git repository, that I
recommend any interested users to test. The only thing you have to
know is that the data format is going to change: Favorites and
Triggers that you add might not be compatible with future versions of
Kupfer.

The data format must stabilize before we can release. (Until now,
Kupfer has no real data format and no real index -- it has a cache,
but caches are such that you can just throw them away and build them
anew. This is why the old Favorites plugin is "simple"; it is only
stored in the cache.)

Unstable does not imply that I think Kupfer will crash or break your
computer, just that kupfer configuration and data might not be
restored from previous versions or saved for later versions. So using
Kupfer from git, it might be that you have to erase all the *.gz cache
files from ~/.cache/kupfer (Quit kupfer, THEN erase the files, start
Kupfer again) to fix errors if they appear.

So we have a longer development period where we can make some breaking
changes, like:

* String review for consistency across similar plugins
* Python package reorganization (?)
* Port all contacts plugins to a new Contacts API (?)

Ulrik