Lifted MAX $RecursionLimit to 512
Support more trailing operators
Slight performance improvement

test the existence of imported names outside the loop
and make sure they are imported before entering the loop
Sample output updated to new MAX

New MAX $RecursionLimit is now 512
Allow many symbols in Protect and Unprotect

This fixes issue #95 reported by langit
Merge pull request #96 from langit/master

Lifted MAX $RecursionLimit to 512