Reducing database access.
Allow vertical scrolling on Network graph
Render graph partially.
Fix minor bug about line overlap.
Add test related to a bug of network graph.
Fix Gitlab::Git::Repository#commit returns wrong commit, if commit_id is "tag name".
Merge giggsey:patch-1 into improve-performance-of-network-graph
Draging network graph is replaced by vertical scrolling.
Merge pull request #3741 from hiroponz/improve-performance-of-network-graph

Improve performance of network graph