Use NSDate for what it is - point in time date/time representation

Don’t try to “convert” dates to local GMT representations - NSDates exist as timezone-less expressions of a point in time.  This in combination with a fix for the wpxmlrpc project prevents issues like #1071.
Updated Pods so dependencies are properly managed for wpxmlrpc 0.3
Updated to Cocoapods 0.29.0
Merge pull request #1080 from wordpress-mobile/issue/737-gmt-date-handling

Use NSDate for what it is - point in time date/time representation