changes
Fixed bug in ActionVolume

A virtual function that is referenced was named wrongly
Install latest doxygen
Solve numerical issues in regtests

I added a script that converts "-0.0000" to " 0.0000" before
making the diff for regtests. This is done only in files
starting with "!# FIELDS "

To avoid false errors I also decreased the precision of a few files.

Fixes #29
Copy regtests to doc
Merge branch 'v2.1' into v2.1-travis-ci
Don't initialize mpi if not necessary
This test was probably meant to be run with 2 processors
Better travis file

Run valgrind tests when [valgrind] appears in git log

Build doc when [makedoc] appears in git log

Use openmp1.5 (standard openmp had a bug making one test fail)

xdrfile is not installed (will be used in 2.2)
Merge branch 'v2.1' into v2.1-travis-ci
Fixed travis file

Check for keywords should take last commit and not
ignore merge commits