- before_kill, after_kill hooks introduction
- add a system to pass extra parameters to hooks (to be able to pass the
  process pid to before/after_kill)
before/after_kill => before/after_signal (better)
SIGKILL is always sent
documentation update
add some tests for before_signal and after_signal hooks
add more documentation and examples for hooks
PEP8 compliance

That extra line was breaking the build.
Merge pull request #1 from amarandon/before_signal_hook

Remove a blank line that's breaking the Travis build
remove all parenthesis here as @tarekziade proposed
Merge pull request #539 from thefab/before_signal_hook

Add before_signal and after_signal hooks