Added new doxygen_upgrade and doxygen_create targets to the DOXYGEN build system module. Clean up CORE build system module.

Document build system targets. Add a rule to the BUILD module that is run if a source file does not exist to show an error to the user, rather than running the check-source rule before each build (slightly faster/more portable and the generated error is then a true make error).

Clean up BUILD module info output formatting, remove explicit gcc-version target and add ability to generate assembly listings of compiled source files for debug purposes.

Fixed missing Win-32bit compatibility sections in the LUFA INF driver files (thanks to Christan Beharrell).

Update the BUILD build system module to early abort and display an error if needed before trying to create the OBJDIR output object file directory.

Upgrade Doxygen configuration files, custom style CSS and DOXYGEN build module for the latest Doxygen release.

Fixed inverted LED driving code for the Arduino Leonardo board. Fixed inverted LEDs_GetLEDs() function implementation for the Benito, Minimus and Arduino UNO boards.

Fix typo in the LED dispatch header, breaking builds for Leonardo board or boards without a LUFA provided LED driver.

Added support for the Arduino Leonardo board. Swap Olimex 32U4 RX/TX LED masks so that it lines up with the Arduino boards.

Added workaround for broken VBUS detection on AVR8 devices when a bootloader starts the application via a software jump without first turning off the OTG pad (thanks to Simon Inns)

Add help text to the project makefiles to help new users get information on the improved build system.

Revert the default DEBUG_LEVEL setting from 3 to 2, as this is apparently causing segfaults on some builds of binutils-avr.

Fix broken code sample section spacing in the Doxygen documentation due to a missing line-height CSS property.

Add hack to the XPLAINBridge project to allow it to compile even if an identical OBJDIR directory exists in the dependant AVRISP-MKII clone project folder.

Split out bootloader HEX generation into separate directories for each bootloader in the maintenance script.

Extend bootloader build test to include all supported configurations including the special XPLAIN board configuration and possible F_USB values.

Force the maintenance script to built bootloaders with F_USB values of 8MHz and 16Mhz - fix when additional architecture bootloaders are available.