Allow environment variable.
Adding support for LED display driver MAX72XX (MAX7219/MAX7221).

1. Implement LCD/IOStream interface.
2. Simple font (7-segment data).
3. Example sketch with font display, analog sample and display as float.
4. Example sketch with IOStream output operator for float/double.
Cleaning up MAX72XX documentation and interface. Improving example sketch.
Clean-up build command; avoid display of configuration for each build.
Fixed build command for ATmega32U4 based boards.

1. Update board attribute (bootloader.path=caterina) to allow build makefile
to recognize USB device.
Refactoring; cleanup.
Fixed "show_boards" target; missed board name with hyphen/minus in name.
Fixed missing board tag for build configuration print.
Refactoring fare; renaming back to original name.
Delete BOARD_TAG

The command "cosa boards" will give this list.
Adding emacs.setup to copy local .emacs file.
Merge branch 'master' of github.com:mikaelpatel/Cosa
Update Cosa build for multiple versions (1.0.5, 1.5.6-r2, 1.5.7 aka nightly gcc 4.8.1).
Cleaning up. New target, avanti, for compile, upload and start serial monitor.
Update build shell script after change; ripple.
Yet another blink example sketch; classical variant with a twist - random delay time.
Adding support for IOStream print and output operator for double.
Cleanup.
Update compiler options for link-time-optimization. Correct Arduino-Makefile setting.
Restoring 1.5.6-r2 as default.