Feature/add freeOnDevice() method

[XL64]

Add freeOnDevice() method to allow freeing memory from GPU before the object destruction. This method is useful to remove temporary working data from GPU space, freeing GPU memory. Add logger using callback for free/allocate when activated.

[rrsettgast]

@wrtobin Are you ok with this in its current form?

[wrtobin]

@corbett5 Randy and I discussed that particular point and IIRC we decided it wasn't a necessary restriction. My concern was primarily preventing users from erroneously de- and re-allocating on device and losing performance as a result.

[rrsettgast]

@wrtobin @corbett5 Can you approve this?