[Featureserver] simplejson version

[Yves Moisan]

> fwiw,
> in my exp recent versions of simplejson are at least "nearly as fast"
> as cjson (within 10%) --using the c extensions in both.

Hi Brent, 

This means I have to compile _cspeedups.c right ?

> for the import, you can see how it's done in vector formats:
> http://svn.featureserver.org/trunk/vectorformats/vectorformats/Formats/GeoJSON.py

I see so cjson is used if it's on the system.  I'm not set with a C
compiler on the windows box I'm working with, so I guess I need to
install MingW and compile cjson ?  Pointers appreciated.

TIA,

Yves