Update CHANGELOG + version for 2019.12.0 (PowerShell#2361)

Add commands to set and unset ISE Compatibility features (PowerShell#…

…2335)

* Add commands to set and unset ISE Compatibility features

* Rename to Enable/Disable ISE Mode.
Some formatting changes due to vscode format document.
Remove option to hide PSIC
Check that user hasn't modified settings from ISE settings before returning them to default.

* use async await

* Update Variable Names.
Add interface for settings.

* Change foreach to for.

* Allow testing on Linux.
Caveat: This is sometimes inconsistent if there were compile errors. Sometimes need to run Invoke-Build Clean before Invoke-Build Test will pick up code changes.

* Add some tests.

* change registerCommand to fix tests

* line length

* move to static

* skip tests on linux

* additional checks

* move to new lib to update timeout

* color check

* launch args

* revert change that shouldn't have been in

* try to run on linux again

* change changelog and no ci on linux

* command explorer

[Ignore] Update CHANGELOG (PowerShell#2272)

Downgrade vsce (PowerShell#2266)

[ignore] update ISE compatibility link (PowerShell#2204)

BACKPORT: Implement PowerShell#1611 - provide dynamic debug config (P…

…owerShell#2084) (PowerShell#2195)

* Address PR comments, change to single promptClean up debug configuration snippet names & descriptions. Remove Launch Pester Tests debug config snippet. The Launch Scriptsnippet gives an example of invoking Pester plus we have code lens to debug Pester tests.

* Remove w/Args prompt debug config snippet

* Switch to int id check in provideDebugConfig

* Address PR feedback, remove path module as it wasn't being used

[Ignore] Target PSES 1.12.2 for build (PowerShell#1992)

Set PSES target version

Add preview to package name

Set PSES target as release/1.12.1