Added the symmetry axioms and probably finished veriT parsing.

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@1614 85d21ef8-add0-11de-ae77-5bfb9c5a3f34
Typo

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@1615 85d21ef8-add0-11de-ae77-5bfb9c5a3f34
Adding a method for cut introduction that takes an expansion proof.

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@1616 85d21ef8-add0-11de-ae77-5bfb9c5a3f34