Updated to version 2.1.7

Updated to version 2.1.6

Fixed warning on Mac OS

Code formatting fixes

Fixed URL encoding bug

Fixed potential race condition if encoding on concurrent threads

Fixed bootrapping crash

Fixed bug in aliasing when using object substitution in -awakeAfterFa…

…stCoding

Fixed README typos

Fixed bug in NSDate serialization

This reverts commit 99733d2.

Updated documentation