God configuration improved

Replace subshell by Sidekiq process and terminate god after deploy:update.
reverse boolean on authorized key remove

When we remove a key, we should only delete
the specific key and not every other key.
Merge pull request #567 from ontohub/fix_nasty_authorized_keys_error

Reverse boolean on authorized key remove. Should fix #559.
Disallowed diff views in robots.txt

concerns #440
Fixed paths for git_daemon

related to #559
Merge branch 'staging'

Conflicts:
	config/deploy/god.rb
god recipe fixed
Merge branch 'staging'
alter startup-script to use valid syntax

The valid syntax for sidekiq queues uses
-q flags before every queue instead of
the comma-separated list.
Look
[here](https://github.com/mperham/sidekiq/blob/master/Changes.md#2172)
for more information.
display_commit more robust

Don't raise an exception if the revision can not be determined.
Upgrade to Devise 3

solves #564
Merge branch 'staging'
add homebrew installed hets to search_path.
bump minimal hets working version number

Importing referenced OWL-ontologies will fail for
earlier versions.
Merge pull request #577 from ontohub/fix_start_development_script

alter startup-script to use valid syntax
Merge branch 'staging'
Merge pull request #578 from ontohub/os_x_hets_management

OS X hets management
Improved ontology formality levels
removed ontology type distributed ontology
Fixed syntax error regarding to formality levels in settings.yml.