Add support to LIFO downloads system in the network queue
Removed unused ispaused method
Delete unusued methods in OCHTTPRequestOperation class
Remove dependency in downloads when it using LIFO queue
I add a documentation changelog
Merge branch 'develop' into Add_FIFO_System_Download_Queue
Merge branch 'develop' into Add_FIFO_System_Download_Queue
I remove a return not necessary
Merge pull request #22 from owncloud/Add_FIFO_System_Download_Queue

Add fifo system download queue