Add capabilities support for palm-sync

[dgollub]

Adding capabilities support for palm-sync should be quite trivial. Since the format of the palm devices is fixed and only have few different versions we only have to determine the version of Addressbook.pdb, Datebook.pdb, CalenderDB and others. And report those via the capabilities interfaces and fallback to hand written capabilities file which get shipped by the palm-sync plugin. Additionally a description file is required, which refers to the best fitting capabilities file.

[puck]

Depending what extra software is installed on the Palm, extra fields might be available. For example Agendus allows linking of records together.