Rearranged datetime created line

Added `avatar_class` option to `link_to_member` so it can be hidden

Made snippet title font heavier

Added file title  bar

Hidden unneeded info from xs screens

Added visibility icon

Reveal file-actions on xs screens

Added comments icon to snippets list items

Refactored no-comments declaration into framework stylesheet

Final touch ups

Fixed snippets_spec

This reverts commit 3e991230.

# Conflicts:
#	app/models/project.rb

Closes #14328

Closes #3701

Split out header into shared partial
Used action partials to have unique actions for shared and personal
snippets
changed back to created date in list view
Switched to using existing color classes

It should now more closly match the styles used in
issues and merge requests with some small tweaks
to be more relevant to snippets

 - Fixed a bug with .btn-sm padding.
 - Changed created_at to modified_at for snippets#index as it seems to
   be more relevant.

- Split up SnippetsController into separate dashboard and explore sections.
- Use consistent page titles, header titles and sidebars between dashboard and explore sections when signed in or not.

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

write_ was renamed to create_
modify_  was renamed to update_

So now in update action we have next code

def create
  can?(current_user, :create_issue, @issue)
end

def update
  can?(current_user, :update_issue, @issue)
end
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Rails image_tag sets the alt-attribute to the filename which causes graphical glitches if the file could not be loaded.

Fixes https://github.com/gitlabhq/gitlabhq/issues/6036.
Signed-off-by: Sven Strickroth <email@cs-ware.de>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>