Updated LockError location and added docs

from threading import RLock, ThreadError

class LockError(ThreadError):

    ERROR_CODES = {

        'ACQUIRE_ERROR': "Unable to acquire. Lock in use by another thread.",

        'IN_USE_ERROR': "Lock in use by another thread."

    }

    def __init__(self, code, lock):

        self.code = code

        if code in LockError.ERROR_CODES:

            self.message = LockError.ERROR_CODES[code]

        else:

            self.message = "Unknown error."

        print("{}: {}".format(self.code, self.message))

from threading import RLock

        ThreadError.__init__(self)

from openflexure_microscope.exceptions import LockError

class StrictLock(object):

    def __init__(self, timeout=1):

        """

        Class that behaves like a Python RLock, but with stricter timeout conditions and custom exceptions.

        """

        self._lock = RLock()

        self.timeout = timeout

class CompositeLock(object):

    def __init__(self, locks, timeout=1):

        """

        Class that behaves like a :py:class:`openflexure_microscope.lock.StrictLock`,

        but allows multiple locks to be acquired and released.

        """

        self.locks = locks

        self.timeout = timeout

    def acquire(self, blocking=True):

        return (lock.acquire(blocking=blocking, timeout=self.timeout) for lock in self.locks)

        return (lock.acquire(blocking=blocking) for lock in self.locks)

    def __enter__(self):

        result = (lock.acquire(blocking=True, timeout=self.timeout) for lock in self.locks)

        result = (lock.acquire(blocking=True) for lock in self.locks)

        if all(result):

            return result

        else: