update README with libc++ build instructions and samples
fix mavericks SDK download link (pointed to 10.8)
build xar only for <=10.5
add -g0 to the clang invocation command to avoid dsymutil from being run (debugging is not supported, but I guess you don't want to debug the resulting binaries anyway if you build them on a non OS X system)
attempt to make the toolchain less path dependent (gcc still breaks though, because of hardcoded paths), but clang and cctools can be moved now
update cctools to 845
add DISABLE_LTO_SUPPORT option (DISABLE_LTO_SUPPORT=1 ./build.sh) to disable linking against libLTO.so
add support for 32 bit systems
add FreeBSD support
update PACKAGE script
