Templatize E57Simple to support double coordinates

[gjacquem]

Hi,

The E57Format lib is overloaded to work with several coordinate types, yet the current E57Simple API only supports float coordinates.
Making the E57Simple Data3DPointsData struct a template enables the use of different types, such as double.

In order to keep the current behavior of the API, the default float template was typedefined using the previous Data3DPointsData name.
A new double version Data3DPointsData_d was also typedefined so that it can be used directly as well.

The intent behind this change is that the last official release of the E57Simple API was using double coordinates, and there are still some use-cases where this level of precision is needed.
This is especially the case when working on large scale scenes - such as we do here at Trimble - and this feature should provide more retro-compatibility to the API.

Regards,
Grégoire

Grégoire Jacquemin | Trimble
Software Development Engineer

[asmaloney]

Thanks Grégoire!

This looks reasonable to me, but I would like to give @ptc-jhoerner a chance to take a look since he brought the simple API over from the original lib.

[ptc-jhoerner]

Thanks! Looks good to me as well. Very nice way to support both float precisions.

[asmaloney]

Thanks @ptc-jhoerner.

And thank you @gjacquem for your first contribution! Much appreciated.