Merge pull request #9 from sngl/experimental-atmel-3.4.3-libusb

Added libusb compiling on Mac
Merge pull request #10 from sngl/experimental-atmel-3.4.3-libusb

Created script to launch avrdude with correct environment variables
Moved avrdude bash script to avrdude-files
avrdude substitution is done only on linux and mac
Compiling libusb-compat-0.1.5 right after libusb-1.x
Replacing LD_LIBRARY_PATH with DYLD_LIBRARY_PATH on mac
On MacOsx DYLD_LIBRARY_PATH is used instead of LD_LIBRARY_PATH. The script checks the OS and use the correct environment variable