fixed a bug in CutIntroduction not supporting grammars with non-terminals starting with index >=0

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@2111 85d21ef8-add0-11de-ae77-5bfb9c5a3f34
fixed a bug in NCutIntroduction (the same as in CutIntroduction)
merge of NCutIntro and CutIntro tbd
Edited the cli command invocations of ncutintro to fit implementation

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@2112 85d21ef8-add0-11de-ae77-5bfb9c5a3f34
prover9: adding function to skip tests if the tools are not installed.

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@2113 85d21ef8-add0-11de-ae77-5bfb9c5a3f34
Deleting old .bak files (left over from the last merge)

git-svn-id: http://gapt.googlecode.com/svn/trunk/source@2114 85d21ef8-add0-11de-ae77-5bfb9c5a3f34