Merge pull request #2 from jeffkowalski/master

Auto-detect ARDUINO_LIBS, ARDUINO_SKETCHBOOK and ARDMK_DIR variables and automatically include /utility folder from libraries.
Updated Readme with jeffkowalski
Allow passing extra flags
Make listing files more useful
Making other *FLAGS += rather than =
Merge pull request #3 from WizenedEE/basic

Making other *FLAGS += rather than =
Fixed a typo in README.

Issue reported at upstream (https://github.com/mjoldfield/Arduino-Makefile/issues/21)
Merge branch 'master' of github.com:sudar/Arduino-Makefile
Added installation notes for Fedora as per Rickard Lindberg's patch; tweaked notes for other OSs
Made the size target look at the ELF file, not the hex, as per Jared Szechy's patch. Craig Leres made a similar comment
Fixed ARDUNIO/ARDUINO typo in README.md as per Kalin Kozhuharov's comment
Only set OBJDIR if it is not already set; if we do set it make it $BOARD_TAG dependent. This follows comments from Matthias Urlichs and Scott Howard
Changed the name of the Debian/Ubuntu package to arduino-mk (just a documentation patch) as per Scott Howard's comment
Only set AVRDUDE_CONF if it's not set, as per Tom Hall's patch
Added support for the USB PID/VID needed for the Leonardo, as per patches from Dan Villiom Podlaski Christiansen and Marc Plano-Lesay
Added changelog
Add knowledge of device-specific assembler
Use variables instead of hardcoded commands
Make disasm more helpful
Change .sym output