fixed MySQL URI Parse Array Merge
Fixed URI Parse Merge with Options in MySQL Class (currently inside constructor)
Created Array Merge Recursive Function in SimplePie_Misc, called from Cache_MySQL

Recursive Merge Array function that keeps values in array1 unless there
are values with the same keys in array2.

Only called from MySQL Cache Class for now.
Fixed Tabs vs Spaces
Call SimplePie_Misc::array_merge_recursive from SimplePie_Cache_Memcache class now, haven't tested
Merge pull request #268 from devlinjunker/master

Fix database URL parsing when merging with defaults

Previously, options which had a default and were strings were turned into
arrays by `array_merge_recursive`. This fixes that behaviour by implementing a
more sane recursive merge.