Changed TermsExtraction so that it extracts always the terms from the expansion proof (note that there is no warning on whether the proof has equality rules by the use of this method). Changed the prnting of statistics.

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@1648 85d21ef8-add0-11de-ae77-5bfb9c5a3f34