Issue577 commands not enabled

Created originally on Bitbucket by colin-hurley (Colin Hurley)

Was already merged in Bitbucket before import, marked as merged by the import user

• Fixes #577 (closed) Various commands not visible/enabled when they should be

  The com.vectrace.MercurialEclipse.def.file definition apparently had issues detecting files in certain contexts. For example, Java files in the Package Explorer apparently don't adapt directly to IFile, but they do adapt to IResource and can then be cast to IFile instead.

• Fix enablement of Add command

  The Add command was apparently failing to enable because multiple iterate tags were in the enable condition. As a result, the inner iterate tags (in the com.vectrace.MercurialEclipse.def.hgUnknown and com.vectrace.MercurialEclipse.def.file reference definitions) were failing because the outer iterate tag (in the command handler block) had already converted the selection list to non-iterable type objects.

  Refs #577 (closed)