Ensure Event handlers are remove on dispoosal of SyntaxMode
Merge pull request #731 from 7sharp9/EnsureEventHandlerDisposalForSyntaxMode

Ensure Event handlers are remove on disposal of SyntaxMode
Ensure all Tip window events are removed on disposal
Merge pull request #732 from 7sharp9/TipWindowEventDisposal

Ensure all Tip window events are removed on disposal
Ensure LanguageBinding cleans up event handlers on disposal
Merge pull request #733 from 7sharp9/LanguageBindingEventDisposal

Ensure LanguageBinding cleans up event handlers on disposal