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 not modified after 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 #296 from bkutil/add_applied_attribute

Add optional crowbar-applied boolean attribute to schema
add travis testing support
Merge pull request #298 from rhafer/travis

add travis testing support
Cleanup trailing white spaces
Disable checksum offloading by default

Most 1g/10g drivers seem to have issues with checksum offloading
when vlans are in use. As those issues are hard to debug and easy
to workaround, lets disable checksum offloading by default.

Add a hidden option in the network.json to be able to set it
to enabled.
Merge pull request #300 from dirkmueller/master

Disable checksum offloading by default