Fix WebHook and special symbols in credentials

When using web hook with credentials secured web resource, one needs to
put the credentials in the hook URL.

If the credentials contain special symbols (e.g. @ or #), it should be
URL-quoted (e.g. %40 instead of @).

But when Gitlab is making a request, it should unquote the symbols
before base64-encoding them.
Add title for "Remove from team" button
Add transition on search box

It's kind of cool trend to use animated-expanding search box nowadays.
E.g. see Github.
Merge pull request #3073 from dmedvinsky/cosmetic-search-transition

Add transition on search box
Merge pull request #3072 from dmedvinsky/add-title-remove-member

Add title for "Remove from team" button
Merge pull request #3071 from dmedvinsky/fix-webhook-auth

Fix WebHook and special symbols in credentials
Add state machine gem
Add base of Event base
Add base of Notifications
Subscription base
Add notofication state to notifications
Replace Event class with OldEvent class
replace events with old_events
Add new relations with new events system
fix errors
fix Notification model
db schema after migration
Enumerize gem added
Classes renamed
Actionable added