Merge branch '6-acquire-non-blocking-lock-should-thrown-lockacquirewouldblockexception-if-lock-could-not-be-acquired' into 'master'

[FEATURE] Acquire a non-blocking lock should throw LockAcquireWouldBlockException

Closes #6

See merge request !1

LockAcquireWouldBlockException should be thrown if non-blocking
lock would block according to the TYPO3 locking api.

This reverts commit 06b77f53.