Merge pull request #76 from AntoineD/master

Fix issue #74
Merge pull request #77 from AntoineD/master

Add computed switch help indentation
dirname: use LocalPath instead of self.__class__. closes #78
atomic file operations
Update CHANGELOG.rst
Update test_local.py
Update fileutils.py
fixes
fdopen in binary
fixes
ProcessExecutionError: derive from EnvironmentError
Update index.rst
rename fileutils -> atomic; add docstrings
release pidfile at exit
prefer lockf over flock
fix tests
fix tests
Update .travis.yml
fix timer thread errors on shutdown
more fixes to timeout thread shutdown