Only show first overload in a series of consecutive overload signatures for navigateTo
Finished up "overload collapsing" for navigate-to.

Current semantics:
  - If an overload lacks an implementation, go to the first implementation.
  - If an overload has any implementation, go to the first one.
  - If there are any declarations between an implementation and any overload, this will split the series of overloads (note that this is invalid code).
Fix compileOnSave with external module
Add fourslash tests to cover external module case
Fix spelling
Address code review
Merge branch 'master' into getEmitOutputExternalModule
Properly marshall diagnostic codes to the managed layer
Add assserts to help diagnose signature help crash #832
Merge pull request #840 from Microsoft/getEmitOutputExternalModule

Get emit output external module
Merge pull request #847 from Microsoft/marshallDiagnosticsCode

Properly marshall diagnostic codes to the managed layer
Don't merge nav bar items that are at different indent levels
Outlining spans for a standalone block shouldn't have the span of their parent.
Merge pull request #849 from Microsoft/navBarMerging

Don't merge nav bar items that are at different indent levels
Merge pull request #851 from Microsoft/blockOutlining

Outlining spans for a standalone block shouldn't have the span of their ...
Merge pull request #804 from Microsoft/overwhelmedByOverloads

Only show first overload in a series of consecutive overload signatures
Merge branch 'master' into sigHelpCrash
Merge pull request #848 from Microsoft/sigHelpCrash

Add asserts to help diagnose signature help crash #832
add declaration target to generate declarations for compiler and services
Respond to code review comments