update kernel-headers to 3.12.6-5

fixes failed install on some (Mac,BSD) systems due to usage of
"install -D".
musl: bump to 1.1.4
add patch for gcc bug #53119
musl: use CROSS_COMPILE instead of CC

this lets musl's Makefile pick up ${CROSS_COMPILE}ar and ranlib.
CROSS_COMPILE is being overridden by CC passed to musl's configure,
so the CC was removed (musl detects it automatically).

closes #34
gcc: default to dwarf2

without this patch, it's not possible to debug binaries generated
with the toolchains on non-bleeding edge gdb.
even if dwarf2 format is manually requested on the command line,
libgcc will be built with dwarf 4 and with it getting linked into
every binary, it's not possible to open them.
defs.sh: fix argument order to be compatible with bb wget

closes #40
binutils: add patch that fixes build without bash

closes #39
README: add note about fork
add patch for gcc bug 61801
or1k support
allow gcc to be fetched from arbitrary URL

This will make gcc to be fetched from $GCC_URL when defined.
Also an optional $GCC_EXTRACT_DIR variable is added to
commodate the case when the extracted directory isn't
of the form gcc-$GCC_VERSION.
Integrating patches into musl-gcc-patches (now on 467512191d79)