Remove environment variable logic

Add pre-built binaries for packages c-w

Update mesa to 17.3.2 (tested on armv7l)

Added a set of formulae for llvm5 and family.

Add dependency libxshmfence for mesa [armv7l]

Rename libomxil_bellagio to libomxil_bellagio.rb

I try to do a clean install of mesa, it shows that it needs libxshmfence.

Add libomxil_bellagio

Update mesa.rb

add --prefix #{CREW_PREFIX} --root #{CREW_DEST_DIR} to pip install

modification for mesa build on armv7l

Bellagio is an opensource implementation of the Khronos OpenMAX Integration Layer
API to access multimedia components.

Create libxshmfence.rb

Update libxshmfence.rb

Update liblapack.rb

Add LAPACK package

Update harfbuzz from 1.4.8 to 1.7.4

Add markdown package

Update manpages from 4.13 to 4.14

Add usbutils package

Add libusb package

Update pciutils from 3.5.5 to 3.5.6

Update coreutils from 8.28 to 8.29

Update python3 from 3.6.0 to 3.6.4