Adding a flag for Cocoa Pods users

Using the Parse framework and SDWebImage frameworks installed via Cocoa Pods gives the same error as described in the Alternatively section of the Add Linker Flag section in this Readme.
I found a solution here : http://www.deanmao.com/2012/12/31/linker-error-using-cocoapods/
Merge pull request #879 from dulgan/patch-1

Adding a flag for Cocoa Pods users
Updated code sample to not use deprecated api
Merge pull request #890 from kyleclegg/master

Updated key filter sample code
minor spelling (forth->fourth)
Merge pull request #893 from asparagui/sp_fixes

minor spelling (forth->fourth)
Merge pull request #6 from rs/master

Merge from Master