Support for iWork 2014+

[pascalbros]

Updated the code and documentation for the new iWork format

[kholia]

@pascalbros Do you have a sample password-protected iWork 2015+ file which you can share with me (dhiru at openwall.com)? I would like to take a look at how the password protection is working in the absence of .iwph file.

Previously, I have written a small parser to extract password hashes from older iWork 2009 / '13 / '14 files (called iwork2john.py). Thanks!

[lechium]

is there any reason this was never merged?