Consider restoring the /usr/local/bin/rpxc-$CMD symlinks

[sdt]

I forget why I removed these, but they are handy for one-liners and stuff.

See #21 and

docker-raspberry-pi-cross-compiler/Dockerfile

Lines 40 to 42 in ac49933

	&& for i in ${CROSS_COMPILE}*; do \
	ln -sf $i /usr/local/bin/rpxc-${i#$CROSS_COMPILE}; \
	done \