fix missing invalidation of the cached resolved DI object in InstanceRequirements
models: get rid of Port#actual_name

This is really an artifact of the old composition port handling.

It fixes an inconsistency between Composition#port_mappings_for
and composition models (closes #12)
Merge pull request #14 from rock-core/fix_issue12

models: get rid of Port#actual_name
gui: fix display of instance requirements

The display code is accessing the pushed selections as well as selections
directly, in order to display them separately. However, they became
protected methods, so use send() to get access to them anyways
Merge pull request #31 from rock-core/fix_instance_requirement_display

gui: fix display of instance requirements
Merge remote-tracking branch 'autobuild/master' into orogen_loaders

Conflicts:
	lib/syskit/instance_requirements.rb