Made convertTime a staticmethod

Logically, it belongs in the data class since that's now the only thing that
uses the function.  But, the function is not dependent on an instance, so we
made it static to make it more generally available should the need arise.
Now Access Proxy object directly through Header object

The Header class originally had a function to return a proxy object based on the
current active header parameters.  We now access the proxy directly through a
header instance.  This necessitated a number of changes in the options file and
fileprocessor file to take advantage of the new methodology.
Only Retrieve Categories Once

During post file processing, was retrieving the category list during every
category check, which was unnecessary.  Now the category list is retrieved once
and the header categories are checked against that list.  Mainly, this should
speed up post times of posts with multiple categories since extraneous XMLRPC
calls are eliminated.