Merge pull request #542 from thefab/unused_commit

unused import
Merge pull request #2 from amarandon/async_experiment

Async experiment with max_age
still some experiments
Merge branch 'async_experiment2' into async_experiment

Conflicts:
	circus/watcher.py
making process with stop command
start to work
add some hints
unit tests ok
set command is now asynchrounous (because of restart)
add a space for flake8/travis build
bad comment (before/after_kill never existed publicly, replaced by
before/after_signal)
Merge pull request #544 from thefab/comment_fix

bad comment (before/after_kill never existed publicly, replaced by before/after_signal)
some progress
some details
exclusive locks between some commands
rm_watcher is now async
more robust (for unit tests)
fix some new problems with unit tests
skipping some tests because they block the whole process
Initial version of the CommandReloader plugin
Follow test naming convention for plugins