Create a new clients/ subdirectory at the top level, and move cli/ and
tui/ into it, as well as nm-online.c (which was previously in test/,
which made no sense).
cli/ was split into two subdirectories, src/ and completion/. While
this does simplify things (given that the completion file and the
binary both need to be named "nmcli"), it bloats the source tree, and
we can work around it by just renaming the completion file at install
time. Then we can combine the two directories into one and just have
it all under clients/cli/.
GLib registers number->string value transforms (meaning that
number-valued properties like NMSettingVlan:id or NMSettingWired:mtu
get loaded into their NmtNewtEntries correctly), but not the
corresponding string->number transforms (meaning changes made in the
entries don't get propagated back to the settings, and due to
http://bugzilla.gnome.org/show_bug.cgi?id=726574, there's no warning
about this). Fix this by registering our own transforms.
