Remove superfluous context.path

It was generating URLs that look like
http://server.example.com/gitbucket/gitbucket/git/user/repo.git (notice
the extra "/gitbucket"?) when the WAR was deployed in Tomcat.
Resolves error when deleting repsository with PR.
Fetch pull request from source repository after updating repository.
Merge pull request #202 from odz/delete-repository-with-pullreq

Resolves Error when deleting repository which has PR.
Merge pull request #203 from olivierdagenais/FixManualMergeUrls

Remove superfluous context.path
Ignore TransportException if the source branch had been removed.
Ignore Exception instead of TransportException
Merge branch 'pullreq-update-in-push' of https://github.com/odz/gitbucket into odz-pullreq-update-in-push

Conflicts:
	src/main/scala/app/PullRequestsController.scala
(refs #211)README.md detection is case insensitive and it also detect README.markdown as same as Github.
(refs #204)Add some way to configure data directory.

1) system property of JVM (e.g. -Dgitbucket.home=PATH_TO_DATADIR)
2) java -jar gitbucket.war --data=PATH_TO_DATADIR
3) Add context parameter "gitbucket.home" to web.xml
(refs #204)Change the option name from --data to --gitbucket.home
Close issues via commit messages
Update README.md
Update README.md
Update README.md
Update README.md
Turn off autocomplete on "Add collaborator" form

You have already created js autocomplete for that input, so it is good to turn off the browser autocomplete. If there are more forms that have custom autocomplete, this change should be applied to them, too.
Fixes issue #216

Added a div element to wrap the buttons so they are vertically aligned with each other. Also converted input and a elements to button elements as Bootstrap recommends: http://getbootstrap.com/css/#buttons-tags
(refs #204)Replace order of ScalatraListener and AutoUpdateListener
Silenced compiler warnings