v2.0-rc1: Release Candidate 1

Change log:

• FAT Filesystem and SD card fully refactored and tested
• Build system simplified with use of find_package(PropWare)
• INSTALL.py replaced with executable installation files
• SPI class moved to inline assembly with fcache

New objects:

• I2C
• WS2812
• PCF8591

Known Issues:

• Filesystem utilities do not allow any action outside the root directory (may not be fixed until v2.1)
• PropGCC is no longer part of installation
• PATH variable is not modified during installation (necessary for CMake in Windows)