Gelencsér Szabolcs / storagedriver

Conflicts:
	storagedriver.py

* remove move_to_trash()
* remove recover_from_trash()
* add exits() which say an image exists
* rework make_free_space()

Conflicts:
	storagedriver.py

disk: implement check_valid_image() and checksum() methods of CephDisk, small rework in download() method
storagedriver: fix make_free_space()

Hostname fix



See merge request !11

util: move CephConnection to util.py

disk: add timeout handling for CephConnection

Modified storagedriver functions:
* list()
* list_files()
* create()
* delete()
* snapshot()
* get()
* move_to_trash(): removed
* recover_from_trash(): renamed to is_exists, and reworked
* make_free_space(): reworked

fix ctime error in make_free_space

See merge request !9

Feature fix celery

See merge request !8

Max files size

fixes #3

See merge request !7

Feature md5sum

See merge request !6

Feature Save As Status

Feature Abort Save As

Make save_as job abortable.

qcow2-snapshot image handled by Process.Popen (qemu-img)
qcow2-norm handled by Threded shutil copy
iso-s simlink is not abortable (fast operation)