[cubicweb-ctl] move to accepting only once instance name per command The rationals behind this decision are: - while in the past managing all instances sytem wide made a lot of sens, pratices have evolved today and we've moved to managing one instance by one - this makes things easier to debug since commands since using them on several instances were making this harder (errors hidden in the middle) - also solve the problem of the return code to have, before it was always 0 which prevented to do things like: ipython --pdb $(which cubicweb-ctl) $command $instance or shell scripts that used it - this simplify the code and is always good to take

^build$
^dist$
\.egg-info$
^.tox$
^.cache$
\.pyc$
\.pyo$
\.bak$
\.old$
\~$
\#.*?\#$
\.swp$
^doc/book/en/apidoc$
\.old$
\.pybuild
cubicweb/server/test/data/slapd.conf
debian/python-cubicweb
debian/*.log
debian/*.substvars
debian/cubicweb-doc
debian/cubicweb
debian/files

syntax: regexp
.*/data.*/database/.*
.*/data/ldapdb/.*
.*/data/uicache/
.*/data/libpython/cubicweb_.*/i18n/.*\.po
^doc/html/
^doc/doctrees/
^doc/book/en/devweb/js_api/
^doc/_build
^doc/js_api/
test-results.xml
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