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.
Rewrote init script.
Changes recommended by @axilleas
Corrections suggested by jacobvosmaer
Fixed failure to stop and added handling of failure to remove stale pid
Add link to project page from admin view
Restart works again, grammar mistakes corrected.
Refactor contributing process to make it more readable and make sure other core team members are mentioned.
Mode User+LDAP functionality from Gitlab::Auth
Move ldap auth to LDAP::User. Removed unused code
Remove include of grack_ldap
Use normal font-weight for file names on tree view
Add 'notes' to path blacklist, fixes #4967
Made script path flexible
Merge pull request #4920 from Rovanion/init-rewrite

Rewrote init script.
Update installation docs to use v1.7.1 of gitlab-shell
Merge pull request #4976 from robertd/master

Update installation docs to use v1.7.1 of gitlab-shell