Use apply_omniauth consistently

Previous implementation means we don't get an access_token, and for folks overriding #apply_omniauth.

Fixes #69
Truncate OAuth key and secret in list view

OAuth keys and secrets can be really long (i.e. with Google's OAuth 2). This causes the list of authentication methods to grow too big horizontally. Truncating the keys solves this issue.

Fixes #73
Log instead of print loading of authentication source

Which authentications sources get loaded during initialization is informational and should be logged as such - and not written to stdout.
Get tests passing again after change to use apply_omniauth
Run 1-3-stable through travis as well
Use spree && spree_auth_devise 1-3-stable branches
1-3-stable-specific travis badget
Use url helper instead of raw url generated based on the site_url spree preference
Updates to make code decoupled from devise.

Conflicts:
	Gemfile
Fix user references to spree_user.
Fix remaining references to :user noticed by @swrobel.
Attempt fallback to social authentication for user.
Add spree engine name in the omniauth auth url helper
Merge pull request #78 from supherman/url_helper

Use url helper instead of raw url generated based on the site_url spree ...