Added maven pom.xml files.
Update generated files
Update gitignore
Adapt to new language build.
Fixes for two-stage build and cleanup.
Made strj and the generator Java projects. Remove dependence on strategoxt.jar for everything.
Update generated build file.
Add project metadata to POM files, required for publishing to the Maven central repository.
Trying to port TS to Symbolsorts SDF3.
Fixed the symbolsorts port by using an auxiliary OptLAYOUT sort for LAYOUT?.
Merge branch 'feature/symbolsorts' into coq-semantics

Conflicts:
	org.metaborg.meta.lang.ts/src-gen/completions/Signatures-esv.esv
	org.metaborg.meta.lang.ts/src-gen/completions/terms/StringQuotations-esv.esv
	org.metaborg.meta.lang.ts/src-gen/pp/Common-pp.str
	org.metaborg.meta.lang.ts/src-gen/pp/Module-pp.str
	org.metaborg.meta.lang.ts/src-gen/pp/Relations-pp.str
	org.metaborg.meta.lang.ts/src-gen/pp/Signatures-pp.str
	org.metaborg.meta.lang.ts/src-gen/pp/TypeFunctions-pp.str
	org.metaborg.meta.lang.ts/src-gen/pp/TypeSystemLanguage-pp.str
	org.metaborg.meta.lang.ts/src-gen/pp/terms/StringQuotations-pp.str
	org.metaborg.meta.lang.ts/src-gen/pp/terms/Terms-pp.str
	org.metaborg.meta.lang.ts/src-gen/signatures/terms/StringQuotations-sig.str
	org.metaborg.meta.lang.ts/src-gen/syntax/TypeFunctions.sdf
	org.metaborg.meta.lang.ts/src-gen/syntax/TypeSystemLanguage.generated.pp
	org.metaborg.meta.lang.ts/src-gen/syntax/common/Layout.sdf
	org.metaborg.meta.lang.ts/src-gen/syntax/terms/StringQuotations.sdf
	org.metaborg.meta.lang.ts/syntax/terms/StringQuotations.sdf3
	org.metaborg.meta.lang.ts/trans/pp.str
	org.metaborg.meta.lang.ts/trans/typesystemlanguage.str

Fixed using the feature/symbolsorts branch code.