add uwsgi provider for WSGI applications
use a single validation error handling function
add one role validation method to be used in child objects
use a validation_error method which also does logging
extend drop target to include the box of servers

Fixes bnc#838662
added methods for validating the existence of a db proposal
allow comma-separated lists as well as space separated ones
extending 'wait for chef' for other states
during node edit, offer user to define intended node role
Merge pull request #777 from MirantisDellCrowbar/feature/uwsgi/master

[feature] add uwsgi provider for WSGI applications
timeout must be integer
remove comment from xml config
Merge pull request #799 from MirantisDellCrowbar/bug/uwsgi-config/master

remove comment from xml config
Merge pull request #798 from jsuchome/timeout

timeout must be integer
added network role
network role
remove 'rexml/document' to get rid of a random ordering keys in uwsgi xml config and notifications for restart service
show Undecided label for no_role
move service and change notifies to subscribes
change init.d to upstart