Merge pull request #36 from DanTup/master

Fix paths to new repo location (Fixes #35).
Remove unnecessary regions
Use PredefinedErrorTypeNames instead of literals
Rename the VS wrapper for DartAnalysisService to avoid name aliasing
Update DartFileChangeTracker to operate as a IVsTextViewCreationListener
Remove several unnecessary uses of EnvDTE
Merge pull request #40 from sharwell/predefined-error-type-names

Use PredefinedErrorTypeNames instead of literals
Merge pull request #39 from sharwell/unnecessary-regions

Remove unnecessary regions
Merge pull request #41 from sharwell/analysis-cleanup

Analysis cleanup