alphasign 0.3.1

Alphasign is handles communication with LED signs using the Alpha Sign Protocol. These include Alpha signs and Betabrite signs by Adaptive Micro Systems, maybe others too, YMMV. This release handles writing "text files" and "string" files to the sign over rs232 serial port, using a fixed memory configuration. Upcoming releases will add "dots picture" files and memory user accesable memory file configuration.