Remove global directive from tests; it's set in .jshintrc.
Merge pull request #485 from XhmikosR/globals

Move global config to JSHint's configuration.
Enable JSHint's `eqeqeq` rule and remove `eqnull`.
Remove unused variables.
Enable strict mode.
Fix test failures after the strict comparison changes.
Enable JSHint's `camelcase` rule.