This adds two new helper scripts that are good for debugging mgmt. Just
build and add `sigtee` to your ~/bin/ along with filter-golang-stack.py
and mgmt_debug.sh and use the later to call mgmt as you would normally.
For example, I might do:
$ mgmt_debug.sh ./mgmt run --tmp-prefix lang examples/lang/hello0.mcl
And if I kill it with ^\ then I'll get a filtered trace at the end in my
$PAGER (which is assumed to be `less`) and this should make my life
easier.
As a cool bonus, this means we use bash, python, and golang all
together!
