Persist-queue

Feature
-------
[GH-127]: Add VACUUM for SQLiteAckQueue

Feature
--------

[GH-100]: support db_file_name when creating queue
[GH-112]: Allow explicit reclamation of resources
[GH-115]: Adding .empty to relevant queues
[GH-118]: add optional autosave feature to file Queue

Fixes
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[GH-96]: Don't log queue item contents
[GH-98]: Fix UniqueQueue dictionary problem with json serializer
[GH-105]: Remove the importing of msgpack when install
[GH-113]: Quote table name for safety
[GH-117]: fix AttributeError in queue.__del__

Others
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Feature:
--------
[GH-73] Enable non-pickle serializers for sqlite3 base queues

Fixes:
-----
[GH-79] Fix issue when storing 0 as value

Others:
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[GH-90][GH-93] Readme update
Move tests/ from project root to persistqueue/ so that it will not pollute the user package

Features

[GH-63] Allow configuring serializer in file based queue 63
[GH-64]Automatic select temp dir 69
[GH-64]Atomic Rename on Windows 54 (File based queue on Windows is now much robust and faster!)

Bug fixes:

[GH-56] File-based queue is unreadable after system hard reset 56
[GH-58] Sqlite3 database self-destructs if app aborted with ^C 58
[GH-61] add resume for ack queue 61

Major change:

- [GH-49]SQLiteAckQueue: A simple and lightweight queue supporting "ack" based on sqlite queue.

Enhancements:

[GH-45]Use the highest protocol version for pickle