add --exclude argument to check-all-merges.py
add --exclude argument to check-all-merges.py

as well as a --config for using a premade config,
and a command for dumping such a config

SEL-Columbia/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,puttarajubr/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,puttarajubr/commcare-hq,puttarajubr/commcare-hq,puttarajubr/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,SEL-Columbia/commcare-hq,dimagi/commcare-hq,SEL-Columbia/commcare-hq,qedsoftware/commcare-hq,qedsoftware/commcare-hq