Cleanup of CheckSQL
 - CVE checking is now a simple hash
 - Removed implicit returns
 - Removed duplicate code from find_scope_calls
 - Removed assignments from if statements
 - Bracketed ambiguos statements
 - Onelined simple if statements
Code cleanup
 - Removed brackets where possible.
 - No more assignments in if-statements
 - Refactored out unsafe argument array checking
Merge pull request #356 from barttenbrinke/check_sql_refactor

Cleanup of CheckSQL because of the F rating in code climate