use manifold-core v0.8.0
sanitize namespace identifiers (fixes #35)

Conflicts:
	src/test/java/org/manifold/compiler/front/TestNamespaceIdentifier.java
version bump v0.2.1
Merge branch 'master' into issue35
remove docblock comment
more descriptive error message
Merge pull request #36 from mtrberzi/issue35

Sanitize namespace identifiers