Allow set group avatar when create group. Not only edit page

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Improve edit page UI/UX

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Merge branch 'new-group-avatar' into 'master'

Ability to upload avatar when create new group

Before this change you dont know you can upload avatar for group until you visit group edit page.

After this change you are able to upload avatar during group creation
Merge branch 'improved-edit-file-ui' into 'master'

Improved edit file ui

* remove ugly borders
* replace small buttons with tabs
* add spinner while diff is loading