Fix 404 error while displaying json files.

It uses params[:id] instead of request.fullpath.
It should fix #3132.
Fix style of network graph.

refs #3258
Using arrowed line only if it connects to not first parent.

It is easy to see which branch is merged.
Merge pull request #3288 from hiroponz/fix-style-network-graph

Fix style of network graph.
Fix lines and line numbers being squashed in File -> blame
fix blame view head nav
Change gollum repo to use https:// instead of git://

A lot of people might have firewalls blocking the git:// protocol. Using https:// makes this easier and matches the other git repositories in the Gemfile.
Change Gemfile.lock repo to use https://
Attribution as mentioned in https://news.ycombinator.com/item?id=5423635
Use real name.
fix xss issue in blame
All involved are mentioned. https://news.ycombinator.com/item?id=5424050
Merge pull request #3303 from dosire/attribute

Attribution as mentioned in https://news.ycombinator.com/item?id=5423635
Merge pull request #3300 from aus/patch-1

Change gollum repo to use https:// instead of git://
Update ruby to latest version.
Merge pull request #3305 from dosire/update-ruby

Update ruby to latest version.
5.0 should no longer be on the roadmap
spelling error
Updated links to gitlab.com and added the last doc files.
security update of crack gem