It is same search like we have at issues page. It allows to quickly
filter merge requests based on title or desription. I copy-pasted some
js code from Issues.js. In future search (filtering) logic should be
refactoed into one class for merge requests and issues
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.
Dmitriy Zaporozhets