Updated NPAPI header files to latest from Mozilla

[apat...@google.com]

With revision 58, nixysa is now using the latest NPAPI header files
from Mozilla. The review is here: http://codereview.appspot.com/150054.

The advantage of making this change is that some more recent features
of NPAPI are now available to nixysa users. For example, Chromium
trunk now supports NPN_ScheduleTimer and NPN_UnscheduleTimer.

I had some issues updating O3D that might affect other nixysa users. A
few things changed since the older headers we were using. First,
"npupp.h" was renamed to "npfunctions.h". So in the O3D code I had to
change all the occurrences of:

#include <npupp.h>

to:

#include <npfunctions.h>

Second, the members of the NPString struct were renamed from
utf8characters and utf8length to UTF8Characters and UTF8Length
respectively. So I had to rename similarly in O3D. I updated the
python code to generate glue that uses these new names but you might
still need to force your glue to be regenerated depending on your
build setup.

I am not aware of any other issues. If you find other things that need
to be fixed in your code or have any problems as a result of this
change please feel free to post here.

Thanks

Al