Revert a bunch of changes related to constants representability.
Changed the way type resolution works in conversions.
Fix a broken test.
Fixed two broken intentions.
Fixed some basic test cases in error intention
Rebuilt the CheckErrorIntention
Fixed all the convert statement to if intentions
Mark two tests as failing.
Remove error message that couldn't be displayed anyway
Merge pull request #995 from dlsniper/fix-955

Remove error message that couldn't be displayed anyway [fixes #955]
add test cases with method from another package