There was a confusion between a "game" and a "table". "tables" was just a list
of Game's. Also a table was "open" as long as it was created but a Game in
state "open" meant that it was open to new players.
This commit removes the "table" terminology, merges TablesFilters into GameState
and implements filtering in the enumeration method.

We can't break HashTable foreach, so implement our foreach with a HashTableIter
instead of calling GLib's so that the table may be modified while iterating
and iteration stopped immediately.

Like for adding tile, place a pawn when Idle (otherwise all actions are chained
since signals are synchronous).

Use the new table listing/selection mechanism from previous commits in bot.
This adds also an optional interactive mode accessible through -i.

Now the resources are installed and a lookup is performed to find them from
either (respectively) an environment var, the user's datadir and the
compile-time datadir.
Also the server is responsible for sharing the xml data so that all clients
get the same thing, from him over network.
Also libovcc is responsible for the DTD files (since it's a sort of spec)
while the actual XML data belongs to the server.

Workaround the load of OVCCGtkMessageInfo as type-func seems currently
sort-of broken (unused), by pre-loading the type forcefully.
See: https://bugzilla.gnome.org/show_bug.cgi?id=786932

This makes OVCCGtkBoard a more normal widget by allowing to change the
OVCCBoard it displays, avoiding the need to create and destroy the
widget.

This gives better consistency by having tile and pawn related signals
next to each other, as well as making the board more self-sufficient
with it getting signals for all changes on it.

Now we don't install other data next to the link, we must make sure the
directory is created.

Make variable "$<" in non-suffix rules is a GNU Make extension, so
switch to suffix rules.

Additionally, make the rules a little more generic by extracting custom
flags to a _FLAGS variable.