XML header support

[lcoq]

Files with XML headers are not supported, as in the example below.
The OFX version given in this header is 202, but I think this header should even be supported on OFX 1.x.

<?xml version="1.0" encoding="utf-8" ?>
<?OFX OFXHEADER="200" VERSION="202" SECURITY="NONE" OLDFILEUID="NONE" NEWFILEUID="NONE"?>