More relaxed parsing of module names during import from forge
Adds missing 'PE 2.7' to the Puppet General preference page
Fixes exception while switching target platform.
Ensures that com.google.inject.multibindings is on pp.dsl.ui classpath

The multibindings fragment is needed by the Forge. The Forge is
injected by the pp.dsl.ui bundle. Consequently, unless this bundle
imports the fragment, it will be missing from the classpath used
by the injector. This commit ensures that the fragment is available.