Update markdown reference to external issues

1. Issue may be not only in jira.
2. Rewrite method for support different external issue trackers
change bash to sh
fix bash-ism
set the collation to utf8_general_ci

I get problems with strange characters in merge requests unless the collation is set to utf8_general_ci

set the collation to utf8_general_ci

I get problems with strange characters in merge requests unless the collation is set to utf8_general_ci

set the collation to utf8_general_ci

I get problems with strange characters in merge requests unless the collation is set to utf8_general_ci
Remove unused title parameter.

It is always overridden by to humanized source branch name by
MergeRequests::BuilService, which is used by new_project_merge_request_path.
Fix not rendered the network graph edge.
Update user_management.md

add rails_env to commands
Update markdown.rb

Fix mistake by @qqshfox report
move env to end of lines
fix link_to by @bwrsandman

Add missing '#'
Document the extra.sign_in_text setting for CE
Update highlight.js to 8.2, fixes #519
add sign-in count

add sign-in count to admin section profile view
add current sign-in date

add current sign-in date to admin section profile view
Add article about GitLab flow.
Add GitLab Flow to the index.
Fix grammar mistakes, thanks Angus
Make tree readme title - a link with anchor to README section

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
add missing config files to check during release process
Adding in snippet search functionality

http://feedback.gitlab.com/forums/176466-general/suggestions/5529795-search-though-snippets