Properly implement %op% for Token::multiCompare

Use tok->isOp() instead of doing it "manually".

This fixes false positives for the C++ template case since
the brackets in "template < something >" are not comparison operators.

Profiling showed using tok->isOp() is actually faster than before (-O2).
Revert "Change location of %op% operator in multicompare"
It's no longer needed with the proper fix for Token::Match().

This reverts commit 8b2adf1391f5ae02040ecf1fdc6c2d422e87c343.