I2C can now be used to re-initialize the peripheral.
Rename MPU60xx_Sleep to MPU60xx_SetEnabled
Improve commenting in I2CdsPIC library.
Code cleanup and modularization improvements.

The I2C peripheral can now be initialized to any proper baud rate with any processor speed.
The MPU60xx functions are now all re-entrant.
Documentation has been further improved for the I2C library.