Very small negligible changes, add javadoc, test case, etc
JBIDE-14298 new extetnsion point to replace previous downloadruntimes

JBIDE-14298 re-instating the cache as we currently fetch remote files during this call.

JBIDE-14298 core activator should use the getter, not the loader
JBIDE-3355 org.jboss.tools.common.text.ext.hyperlink.AbstractHyperlink review

Added static execute(IFile, ICommand) method and ICommand interface to
execute code with guarantee to release Structured model used to
get Structured model instance. Using this method many calls wrapped with
try/try catch could be eliminated.