Fix numbering in 6.3-to-6.4.md
Unify markdown syntax for Bash commands
use the iid to generate the link_to_merge_request_diff_line_note instead of id
Reword upgrade -y comment, improve layout and allow just y.
Fix 500 error in Ruby 1.9.
Better submodule links.

Detect if submodule is hosted on this GitLab server, gitlab.com or github.com.
Hash links directly to commit in repo.
Replace badge to labels, because twbs3 doesn't supprot colored badges
Update upgrade guide if you have more than one backup .tar file
Show avatars of groups on profile screen that user belongs to
Uniform description.
Also change the description in the help.
 Merge branch 'better-description-and-50k' into 'master'

Better Description And 50k
Add tests for groups avatars check on user page
Merge pull request #6267 from robertd/feature-groups-on-profile-screen

Show avatars of groups on profile screen that user belongs to
Merge pull request #6261 from skv-headless/badge_to_labels

Replace badge to labels, because twbs3 doesn't supprot colored badges
 Merge branch 'feature/submodule-links' into 'master'

Better submodule links

Detect if submodule is hosted on this GitLab server, gitlab.com or github.com.
Hash links directly to commit in repo.
Update changelog for #6267
Minor README fix

I guess it should be "...*more* than 50,000"
Fixes #6187, Update dead links
Fixes #6073, Update grammer in MR accept form