cmd/tsr: delete collector

Good bye, cruel world.
fabfile: remove file

We don't use it anymore.
misc: clean directory

There were lots of old stuff in this directory.
Makefile, docs, misc: remove references to the collector
provision: remove CollectStatus

Die collector, die!
provision/docker: remove CollectStatus

The logic is still useful for the coming fixContainer handler and
command.
provision/docker: add handler for fixing containers
provision/docker: add /docker prefix to URLs in the API

Closes #833.
extract provisioner checkers from tsuru/config to cmd/tsr/. Related #714
api: run handler doesn't lock app
change tsr api cmd to always check config and then it starts.
add release notes to tsr api cmd. Related #714
update tsuru test conf
provision/docker: add command to fix containers

This is what collector used to do, but collector is no more :)
provision/docker: add test for AdminCommands

Also added fixContainersCmd to the list returned by AdminCommands.
cmd: show 'not authenticated' message to all 401 responses
provision/docker: call fixContainer on dockerProvisioner.Start
docs/release: add link to the 0.5.1 release
cmd/client: fix year in copyright header
docs/releases/tsr/0.5.1: improve wording