* Added basic Nvidia NVML library support and power usage sensor
* Added basic Nvidia NVML library support and power usage sensor
* Added Initialised check
* Made NvmlDevice internal
* Code formatting
* Move NvmlDevice and NvmlReturn to separate files
* Move code from NvidiaNVMLGPU class to NvidiaGPU class
* Replace call to SetDllDirectory with LoadLibrary/FreeLibrary and code formatting changes
* Made native methods private
* Fixed p/invoke definitions, removed unnecessary try/catch blocks. Code style cleanup
Campbell