1) Moved the calendar types location to a sub-folder in the calendar directory.
2) Removed/moved language strings.
3) Removed calendar types that should be downloaded as plugins.
4) Removed a Non-English language pack for the Gregorian calendar type that
should be downloaded separately.
5) Removed custom files responsible for checking for updates and uninstalling
calendar types, which should be done by core.
6) Removed JS from the calendar_month block as there is no non-JS alternative
provided and the JS written does not make use of the YUI library to ensure
multiple browser support.
7) Removed code from the base class responsible for creating timestamps that
are saved in the DB.
8) Added PHPDocs.

Note: In the original patch we are editing core functions responsible for saving
time in the database in the calendar base class. This is very dangerous, we do
not want to touch these functions as it could cause a complete fubar of the
database. There are places we are forcing the use of the gregorian calendar as
we are passing dates generated by the PHP date function, where as sometimes
we pass dates from usergetdate (which was being overwritten to return the
date specific to the calendar). We can not expect third party modules to
change the calendar type depending on the format they pass to these functions.