Merge branch 'hotfix/128'

Close #128
[#85] "current" manual version

- Added to "version" constraint the ability to specify "current"
- Injecting Manual PageController with latest version
- Checking if version specified is "current"; if so, using latest
  version
- Checking if version specified is latest version; if so, redirecting to
  "current"
[#85] Inject canonical rel into manual pages

- If 1.* page, inject link to latest 1.* manual page
- Otherwise, inject link to "current" version
Merge branch 'feature/85' into develop

Forward port #85