rs/SDWebImage — pull request #351 by Vyazovoy (2013-03-27 16:54:32+00:00)
Title: New name for SDWebImageDownloaderQueueMode type, typo fixing, strong cycle fixing.

To avoid of logical inconsistencies in naming I rename SDWebImageDownloaderQueueMode because "queue" notion is a FIFO only, but LIFO is a stack, and if we give the type a neutral name, we can avoid logical inconsistencies. Added description for renamed type, fixed typo and fixed potential strong cycle in Example.