fix(setToolMode): tests and consistent behavior for mouseButtonMask
fix(setToolMode): tests and consistent behavior for mouseButtonMask

Forcing a minor version bump because I missed using the correct syntax for this PR:

https://github.com/cornerstonejs/cornerstoneTools/pull/903#issuecomment-510518564
cornerstonejs/cornerstoneTools,cornerstonejs/cornerstoneTools,cornerstonejs/cornerstoneTools,chafey/cornerstoneTools