dedupv1_test uses configuration file ~/.dedupv1_test

It is possible to configure the "temp dir" in the configuration
file, so that it is not necessary to provide it each time.
If a temp dir is used on the command line, then the command line value
is used.
Fix method signatures of all filters
Add a new dedup system test.

This also fixes a undefined behavior in a test.
Change format source scripts and add a git hook that ensures style.
Update protobuf from 2.3.0 to 2.5.0

The updated version promises "various speed improvements".
Fix on using Python 2.7 for now
Fix on using Python 2.7.

As simplejson is now always available as json module. simplejson
is dropped