cmd: move commands

cmd/tsuru -> cmd/tsuru-base (package tsuru)
cmd/tsuru/ops -> cmd/tsuru-admin (package main)
cmd/tsuru/developer -> cmd/tsuru (package main)
cmd/tsuru-admin: don't use unqualified imports for gocheck

Related to #330.
cmd/tsuru-admin: add tokenGen command

This command will be used to generate user tokens.

Related to #389.
cmd/tsuru-admin: register token-gen command

Closes #389.
cmd/tsuru-admin: version 0.1.1
cmd/tsuru-admin: fix test suite

Should fix the build.
cmd/tsuru-admin: fix token-gen output
cmd/tsuru-admin: version 0.1.2
cmd/tsuru-admin: added --export (or -e) flag to token-gen command
cmd/tsuru-admin: fix token-gen registration
cmd/tsuru-admin: using the export flag in the token-gen command
cmd/tsuru-admin: version 0.1.3
cmd/tsuru-admin: version 0.1.4
cmd/tsuru-admin: version 0.1.5
cmd: remove Doer interface

We don't use it. We never did.
cmd/tsuru-admin: version 0.1.6
cmd/tsuru-admin: version 0.1.7
cmd/tsuru-admin: version 0.1.8
cmd/tsuru-admin: version 0.1.9
cmd/tsuru-admin: version 0.1.10