v2.0-beta5: Flexible Printer

Change log:

• Create PropWare::Printer class
• Move PropWare::UART's printf method to PropWare::Printer
• Use templates to provide on-demand access to each of the print methods
• SD class has begun massive overhaul
• *.dat files now compatible

Known Issues:

• SD and Filesystem classes are no-where near complete
• Spin files still not compatible