Add optional crowbar-applied boolean attribute to schema

We add a crowbar applied attribute to mark the proposal as applied after the
chef run. This allows the UI to show that the current form of the proposal has
been 'applied' successfully (i.e. chef-client completed the run w/ success) and
that the proposal was then not modified since that.

Update the proposal_schema_revision, so we can add the attribute to schema for
('3rd party') barclamps that currently do not have it.

Refs: crowbar/crowbar#2044 (which adds this attribute to barclamps which lack
it), crowbar/barclamp-crowbar#1068 (which marks the proposals as applied) and
https://bugzilla.novell.com/show_bug.cgi?id=877486
Merge pull request #90 from bkutil/add_applied_attribute

Add optional crowbar-applied boolean attribute to schema
Remove trailing whitespace
Allow the admin node for ipmi-configure/discover

By default it seems the admin node is included in the
proposal, but when you try to save/apply it, you get
the error message that the proposal cannot be saved/applied
due to the role not being valid for admin. Since the
admin node has a central role here it seems, we should
allow it.
use the is_admin? Crowbar helper instead of the class var
[SUSE] Added xen unsupported product