Add client_max_body_size to nginx site

Added the client_max_body_size declaration to the nginx server block to prevent 413 errors when http post body is larger than the default (1m).
Merge pull request #5610 from demosdemon/patch-1

Add client_max_body_size to nginx site
Merge pull request #5733 from bke-drewb/issue-5716

Issue 5716 - Allow removal of avatar
Improve UI for stacked nav-pills

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Modify logo a bit
Add cache expiry on avatar creation/removal

Query by user id only, not projects, too.