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.
Add link to project page from admin view
Refactor contributing process to make it more readable and make sure other core team members are mentioned.
spelling mistake.
Added git command to change shell to 1.1.0 to make sure the check passes
Improve commit diff

* show highlights when replace empty line with content
* show inline diff when replace line with spaces with content
Add group membership api

Change-Id: I5b174bba02856ede788dcb51ec9b0d598ea7d0df
Fixes for @randx

Change-Id: I3b15ae34c0957a0f4026e1886c92a9770e9d170e
Merge pull request #4990 from karlhungus/feature_group_membership_api

Add group membership api
-i flag allows sudo to work for git users using rvm that is not being used by
root user (su might be better)
Fixed description.
Fixed Import Bare Repositories instructions to match rake task.
Forgot to fix the comment instructions.
Merge pull request #5013 from clayzermk1/master

Import Bare Repositories instructions/description are incorrect
Improved large commit handling.

Previously, only number of changed files mattered. Now, number of lines to render in the diff are also taken into account.

A hard limit is set, above which diffs are not rendered and users are not allowed to override that. This prevents high server
resource usage with huge commits.

Related to #1745, #2259

In addition, handle large commits for MergeRequests and Compare controllers.

Also fixes a bug where diffs are loaded twice, if user goes directly to merge_requests/:id/diffs URL.
Merge pull request #5014 from bladealslayer/feature/big-commit-improvements

Improved large commit handling.
Consistent status.