Based on a patch by qingdoa daoo.

Set defaults similar to Win XP for Kashida and set the default char in
ScriptGetFontProperties.

Also make sure the debug registers are properly copied to the context
when set.

Don't allocate memory for the thread error structure until it is
needed, as it is quite large and wastes memory for threads that don't
call any wininet function.

Free all pointers by default, except for conformant strings.
Conformant arrays should always be freed.
Add FC_CVARRAY to list of known types to avoid a FIXME.