Accuracy and accelerometer improvements

1. Improved accuracy and smoothness
2. The base motor gear backlash is accounted for in software. The arms' backlash is to be done in next versions as it is a terrible and nasty workaround to the mechanical design flaw and requires a not straightforward implementation
3. GY-521 modules can be read on RAMPS at any time online in the user program (as opposed to SPI accelerometers on FPGA which can be read only when Arduino boots and will always return same results after that to the user program)
4. Added a safety net that turns off laser when there are no more commands in the queue in Arduino, which can be an indication that the user forgot to turn it off or something went wrong with the user program
5. I2C error detection implemented and recovery procedures added
6. Project restructured (it has become cluttered with growing number of examples and actual software all in one folder)