Add pin definitions for analog pins and workaround Serial1 issue

* Defined pin mappings so the Analog inputs can be be used as Digital I/O
* Cleaned up warnings and strict-aliasing issues
* Added a workaround for issue #2
* Fixed an array overrun with external interrupts
* Fixed compile error when using Flash strings
* Cleaned up toolchain build script to better report errors and stop
* Fixed errors in the build script that prevented a successful build of all tools