Allow caching of data sent with events and requesting such data

Add atspi_event_listener_register_full, to request that particular data
be sent with an event, and cache the data for the duration of the event
callback.

This also extends the D-Bus protocol, adding an a{sv} to an event to send
this data along, but we will still read events without this array added for
backwards compatibility (and compatibilllity with QT-AT-SPI, which does not
send this data for now).

https://bugzilla.gnome.org/show_bug.cgi?id=708695
Release v2.11.5
build: Fix srcdir != builddir from git

As used by Continuous.
Added atspi-accessible-private.h

On commit
6395af932862454ed292d3623c18c59218ecbe7e
atspi-accessible-private.h started to be used, but not included.

https://bugzilla.gnome.org/show_bug.cgi?id=723601
Updated Brazilian Portuguese translation
Updated Spanish translation
Updated Galician translations