Add ChainNoResultException for aggregating ChainProvider exceptions.

Create ChainNoResultException class
Update ChainProvider::getGecodedData/getReversedData methods to
aggregate/throw new exception.
Add tests.
Remove add/setException methods. Remove @access/@return annotations.
Move $exceptions property above methods.
Merge pull request #264 from benglass/master

Add ChainNoResultException for aggregating ChainProvider exceptions.