* Make sure errors are consistent when providing null vs empty key files during signing

* Addressed PR Comments

* Treat empty CryptoKeyFile as null

* More PR Comments

Add integration tests for F1 help

Add VSI tests for Navigation Bars

* Add integration tests for keyword highlighting

* minor cleanup

* Use new APIs

* Verify highlight spans

* Delete extra file

Add a test for VB line commit

Merge dev15.2.x to master

Add option to run just netcore integration tests

Fix null ref in initialize-parameter.

Revert "Disable BasicIntellisenes.TypeAVariableDeclaration until #18397 is fixed"

Disable BasicIntellisenes.TypeAVariableDeclaration until #18397 is fixed

No scrollbar in Code Style preview pane

Make the "Description" column in Code Styles Options a "dataitem" control

Improvements to IOperation test dumper 

Enhance IOperation dumper to dump snippet of syntax and child property names. I have also fixed the existing IOperation tests.

Include captured symbols from display classes passed as arguments

Unify code around remote processing in SymbolFinder.

More cleanup of SymbolFinder.

Name internal helpers more clearly to make it more obvious what they are doing.