[565000] performance impact of org.eclipse.emf.codegen.jet content type

Reduce the file-patterns for jet content type to a single pattern
exploiting the implementation details of
org.eclipse.core.internal.content.ContentTypeCatalog.toRegexp(String)
which converts a file pattern to a regular expression.

Also eliminate NPEs for JET files in a project without a JET nature.

Signed-off-by: Ed Merks <ed.merks@gmail.com>
2 files changed