mergy tool

[Harald Sitter]

since I can't be bothered to discuss a kubuntu folder on git.debian
right now -> merge tool
https://github.com/apachelogger/kubuntu-repo-merge

-o = origin
-t = target
last argument = subdir to ls on git.debian for a list of repos (e.g.
applications/frameworks/plasma)

-o can be defined more than once the origins are tried in order of
appearance so if one runs -o master -o experimental that would first
try to derive from master and if that is absolutely not possibly it
would try to use experimental.

if an origin exists and the target exists it merges origin into target
if an origin exists but no target the target is newly created by
branching origin
if no origin exists it will whine a bit but move along
if a merge fails it will abort which unfortunately right now means
that one has to restart the entire process

pushes do not happen until all repos have been processed
pushes do not happen until the user explicitly instructs the script to
continue (after having inspected the results the script created)

the entire script works on entirely pristine clones (i.e. it will
clone everything into a tmpdir) as to avoid pushing rubbish,
unfinished work commits, incorrect changes, dead repos, dead branches,
getting confused on dirty repos etc etc etc