Merge remote-tracking branch 'origin/dsander-omniauth'

Conflicts:
	Gemfile.lock
Add "chains" to represent runner-target relationships between Agents.
Provide a target agent select box for an agent that can run other agents.
Show target-runner relationships in a diagram.
Add SchedulerAgent, which periodically runs other agents.
Add a spec for how the before_save hook should work.
Store an agent ID in the local storage rather than stashing it in a tag.
Fix the schema version.
Rename "runner" to "controller".

This is done in preparation for adding an ability for an agent to
enable or disable other agents other than running.
Improve the description.
Disable second precision schedule by default to prevent service abuse.
Add control action types "enable" and "disable".
Use error for error, not log.
Set charset/collation properly for each text column if using MySQL.

With this change, Huginn is able to store up to 4-byte UTF-8 characters
in its database.  This should fix #286.
Add support for Ruby 1.9.x.
Fall back utf8mb4 to utf8 if the server does not support it.
Follow the default collation of Rails rather than MySQL.

`utf8*_unicode_ci` is known to be problematic in some languages like
Japanese, but hopefully it wouldn't do harm in practice in our case.
Merge remote-tracking branch 'origin/master' into set_charset_for_mysql

Conflicts:
	db/schema.rb
Add app.json.
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