- common.mk has been tweaked so that the OpenWrt compilation process is
more flexible: one can now choose an OPENWRT_TARGET and the
OPENWRT_ROOT instead of just the OPENWRT_VERSION.
- The OPENWRT_VERSION's default value trunk" has been removed.
- Makefile_atheros_openwrt has been deleted, since with recent OpenWrt
versions (12.09) everything should compile just fine, and we are not
specific to the atheros target any more.
- INSTALL.t2t has been updated to reflect these changes, and a new
section was added to explain how to compile your own toolchain.
Clang compiles faster than GCC and is supposed to give more meaningful
error messages, so let's use it at least for development.
OwlPS Positioner does not compile with clang++, so we are stuck with g++
(or colorgcc).