add rake tasks for web hooks management
add help page for web hooks management using rake tasks
Update logic for validates_merge_request for tree of MR

For case:

Merge request №1: branch "feature" to "release" and remove "feature" branch

Merge request №2: branch "release" to "master" and remove "release" branch

Merge request №1 - broken :(
Remove -y option when removing puby1.8

Since it is easily could break installations running on the server - hence the person doing the install should be able to make the decision to remove himself.
Added git command to change shell to 1.1.0 to make sure the check passes
Added .ruby-version & .ruby-gemset in .gitignore
Corrects the update document to match the version of gitshell specified in the install document (1.7.1)
Drop support of root namespace in model
Don't show users password change page if ldap users
Merge pull request #5117 from karlhungus/feature-password-update-skipped-when-ldap-user

Don't show users password change page if ldap users
Merge pull request #5112 from hiroponz/drop-support-of-root-namespace

Drop support of root namespace in model
Add author and issue id warning.
Merge branch 'changelog-specifics' of /home/git/repositories/gitlab/gitlabhq
Merge pull request #5099 from yatishmehta27/gitignore-changes

Added .ruby-version & .ruby-gemset in .gitignore
Merge branch 'master' of https://dev.gitlab.org/gitlab/gitlabhq
README improved. Removed travis badge
Add author of new init script
remove old assets before compiling
Prevent empty public projects from throwing exceptions

GITLAB-1279 (GITLAB-1264)

Change-Id: Ifb5b4313bc91fae720f8ef5c36152c45e9d38934
Merge branch 'update_changelog' of /home/git/repositories/axil/gitlabhq