Ignore ./idea directory.
Implement Lock (data object for locks).
Make Lock take a timestamp string rather than a DateTime object.
Use Lock class from DbDriver.
Give a warning rather than a notice if stale lock found.
Remove unused code lines.
Add PhpDoc.

    Remove specs for getters.
Merge remote-tracking branch 'origin/master'

Conflicts:
	spec/Ingenerator/RunSingle/LockSpec.php
	src/Ingenerator/RunSingle/Lock.php