OTHER: Honor optim flags in CFLAGS and CXXFLAGS

-g -O0 was forced in the main wscript. THey are now added only
if no -O<n> flag is already in CFLAGS and CXXFLAGS.
OTHER: Use literal format string in rb_raise()

Prevent errors with -Werror=format-security flag.
OTHER: Add missing result value in ruby bindings.
OTHER: Remove unused value in ipc enum

CMD_COLLECTION_SYNC has been replaced in to a new object.
OTHER: Add xmmsv_list_index_of () function.
OTHER: Fix warning in bind_all_references()

xmmsv_coll_operand_add() was called even if the operand was already
in the list. It now checks for its existence first.
OTHER: Fix typos.
OTHER: Fix man page errors.
BUG(2530): Stricter fetchspec validation.
BUG(2478): Add 'cluster-fallback' to cluster-(list|dict).

By default media that doesn't have the attribute specified in
'cluster-field' when 'cluster-by' is set to 'value' will now
be dropped. The user of the API must provide a 'cluster-fallback'
where all media missing the attribute will be collected.
BUG(986): Expose xmmsc_broadcast_medialib_entry_removed.

This is not really ideal. It would be better to have removed
be a part of a xmmsc_broadcast_medialib_entry_changed, but
that function is incorrectly taken by the _UPDATE IPC
message so this will have to do for now.
BUG(986): Add broadcast_medialib_entry_removed to python clientlib.
BUG(986): Add broadcast_medialib_entry_removed to ruby clientlib.
BUG(986): Add broadcastEntryRemoved to C++ clientlib.
BUG(2093): Add float support to python clientlib.
BUG(2093): Add float support to ruby clientlib.
BUG(2093): Add float support to perl clientlib.
OTHER: Fix broken indentation in value_utils.c.
OTHER: Add XMMSV_TYPE_FLOAT support to test utils.
BUG(2479): Use XMMSV_TYPE_FLOAT for aggregate=avg.