* misra.py: R14.2: Verify for counter modification
Add additional check to detect modification of loop counter in loop
body. Related issue: https://trac.cppcheck.net/ticket/9490
Add small fix that treat all assignment operators defined in N1750
6.5.16 as has side affects. This will affects rules 13.1, 13.3, 13.5
and allow to catch some false negatives.
* Add tests for fixed FPs for R13.{1,5,6}
* fix
* use isAssignmentOp from cppcheck data
* remove unused set
* handle case with empty body or syntax error
* add test with outer variable
* Fix FP in nested loops, add tests
* Fix FP on outer variables
* Fixup false positives for not loop counters