Rudimentary template support, excluding tagging.
Added tests and baselines for templates.
Merge branch 'letAndConst' into templates

Conflicts:
	src/compiler/diagnosticInformationMap.generated.ts
	src/compiler/diagnosticMessages.json
Added support for tagged template strings, updated baselines.

Still need to implement some error recovery and add tests.
Better test coverage for templates in object literals.

These tests still need to be fixed.
Added tests for tagged templates. Some should fail when we do typechecking.
Tests for tagged templates.
Added syntactic classification for templates; also made 'spans' a NodeArray.
Merge branch 'master' into templates
Addressed CR feedback.
Changed Debug.assert's first parameter to a boolean.
Renamed certain functions in the parser to more accurately reflect behavior.
Missed a use when fixing Debug.assert
Fixed emit for parenthesized template expressions.
Omit empty template tail literals.
Merge branch 'master' into templates

Conflicts:
	src/compiler/checker.ts
	src/services/services.ts
Disabled completion list entries in template literal parts for the LS.
Merge branch 'master' into templates

Conflicts:
	src/compiler/diagnosticInformationMap.generated.ts
	src/compiler/diagnosticMessages.json
	src/compiler/types.ts
	src/services/utilities.ts
Adding type aliases to language specification
Merge branch 'master' into templates