Fix exceptions on DTE.ActiveDocument

Close #653.
Merge pull request #654 from dungpa/active-doc-exception

Fix exceptions on DTE.ActiveDocument
Recognize long identifiers from type extensions

Fix #655.
Merge pull request #656 from dungpa/unused-opens

Recognize long identifiers from type extensions
Fix wrong ranges of generic type symbols

Close #488.
Fix a related bug in Find All References
Always try to rename the word under cursor

Fix #620.
Fix a few build warnings
Merge pull request #657 from dungpa/rename-generic-types

Fix bugs related to renaming generic types
Handle modules/namespaces with global prefix

Fix #658.
Only trim global namespace if it is an exact prefix
Merge pull request #659 from dungpa/global-namespace

Handle modules/namespaces with global prefix
Handle record fields while checking unused open declarations

Fix #661.
Merge pull request #662 from dungpa/record-value

Handle record fields while checking unused open declarations
No longer force saving projects when project items change

Related to #616.
Merge pull request #663 from dungpa/fix-saving-project

No longer force saving projects when project items change
Complete the skeleton for Navigate to Metadata
Add basic signature generations for entities

Support modules, types, records, unions, enums, functions/values and
members.