This reverts commit 94c2516a, reversing
changes made to ae44e5ec.

Advanced cache

Fixes #1993

* Build missing cache values in background job after each push
* Store commit_count in project table. Refresh in background job
* moved repository size calculation in background job


## Advantages

Every time push is triggered - we build cache for project even without user visiting project page. 
That means first visit is as fast as others now. This is especially good for active projects where people have some requests fast because of cache and some slow - because cache was build in their request. 

Between cache expired and cache built we we had gap when Linux repo can give 502 error because calculation commits count takes 30 seconds or even more. 
Using value from database fix this problem. Before cache is updated you see old value from database. After - you see new one. 

Basically this merge request is super win to GitLab. We don't do some heavy operations in user request but instead in background job. 

## Temporary problem

After this migration all projects will have `0` commits in database. It fill be replaced with real value on next push. I did not add recalculation to migration because it will last forever on big instances.  Can be fixed by adding rake task which will go in background on live instance without downtime

See merge request !986

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

As of Ruby 1.9, this is the correct way to handle `respond_to?` for
methods implemented by `method_missing`.

See https://robots.thoughtbot.com/always-define-respond-to-missing-when-overriding

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

* count opening of issues and merge requests
* dont trigger git repository - use events from database
* much-much faster since does not affected by repository size

This MR extends the commit calendar so it searches for commits made with every email address the user has associated with his account.

This fixes one of the problems mentioned in gitlab-org/gitlab-ce#1162 and makes the behavior of the commit calendar as described in the profile.
"All email addresses will be used to identify your commits."

Abstracts away the lower-level implementation details from the
Repository model.

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

The `GitStats` class has been removed from gitlab_git, so parse commits
directly in `Repository#graph_log`.

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

* remove commits stats page (will be replaced by graphs)
* remove additions/deletions from graph because of bad performance
* keep graph logic in gitlab

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>