Revert "Merge pull request #444 from Microsoft/newCompilerLS"

This reverts commit ae5f4c26171cc56bdff56e2893dc8ac113596270, reversing
changes made to 2f963743c4da421cc0a2fbf00a209dfff7f9aac4.
Merge pull request #459 from Microsoft/revertLS1

Revert the previous language service merge.
Merge branch 'master' into newLanguageService
Revert "Merge branch 'master' into newLanguageService"

This reverts commit d135fa43f50e6c22053075b36288a43ed655cc01, reversing
changes made to 7ddc00cba9a691c4e5ea5bde00da06695fc00546.
Stop referencing 'this' in functions.
Add todo comment tests.