Support for Arduinos with dif pin cnts

Support for Mega and other arduinos with more or less than 16 digital
and 6 analog pins.
Check for pin PWM capabliity on set PWM output
Added Voltage / Temp / Clock / etc.

Added functions for
* quick display
* added analog voltage and digital pin capability to pin listing
* added erase EEPROM function
* added show internal AVR voltage
* added show internal AVR temperature
* added show uptime clock
* added show free memory & EEPROM size

* a couple more fixes to support non-UNO arduino pin counts
reboot command, fix for pincounts

Added a reboot command
Fix for overflow on pincount eeprom read / write
Merge pull request #5 from norpchen/master

Support for Arduinos with dif pin cnts