Added the "HPPOSLLH using double" example

[PaulZC]

I'm proposing we replace ZED-F9P\Example9 with a new example showing how to use the HPPOSLLH functions using double. But this will only run on platforms like the Artemis which provide full support for 64-bit double. What say you?

[nseidle]

This compiles for both Uno and Artemis. I think you should add a

if (sizeof(double) < 8) { Serial.println("This is a bad idea!"); } 

or something similar in there because the output looks just ok enough to use. But the Uno (that down converts doubles to 4 bytes) outputs some very invalid GPS coordinates.

I like this example a lot. There will be lots of folks who have a capable platform and just want the max float precision output.

[nseidle]

Add check for doubles that are less than 8 bytes.

[PaulZC]

Great suggestion - thanks!
Added. Tested on ATmega328P and Artemis. Merging shortly.