Tag version 0.3.4

Tag code version used for submitted ipdps12 paper

Add visit file and write mesh interface

This is a bugfix release.

Version 0.3.1 is now free software.

It seems that p4est is working cleanly.

Update to libsc v0.5.4 and bump the version to v0.2.4.

Update to libsc v0.5.2 and bump the version to v0.2.2.

Update to libsc v0.5.1 and bump the version to v0.2.1.

Some fixes to release v0.2.0.