[ngf] Add libcanberra-using sink.

This involves significantly less latency than the gst-using sink. There is some
low-hanging fruit there that may help latency, but for really simple UI elements
that just want to be heard Right Now, using libcanberra is beneficial as we can
also make use of sample caching, etc.

Done-with: Juho Hämäläinen <juho.hamalainen@oss.tieto.com>
[canberra] Set stream properties specified in the effect on the canberra context.

This hopefully makes volume of canberra-using events be what they should be.
[canberra] Only cache samples once, on the first use.
Merge pull request #14 from rburchell/canberra

libcanberra-using ngfd plugin
[ngfd] make ffmemless optional, as it won't load on VM
ffmemless: Rename settings environment variable

The original plan for the settings environment variable was that
we could use the same settings file for qtfeedback and ngfd.
Unfortunately QSettings cannot read glib's .ini file format,
and vice versa glib cannot comprehend settings values without
bracket header.

So, change the ngf environment variable to be different from
the qtfeedback one, so that separate device/distro specific values
can be set in separate files for qtfeedback and ngfd.

Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi@jollamobile.com>
Merge pull request #16 from kjokinie/master

[ffmemless] Rename settings environment variable
tests: allow execution out of build tree

Relates NEMO#682
[packaging] Package tests

Relates NEMO#682
Merge pull request #11 from martyone/master

Package tests
Remove session file reading.

We always get the session bus set up for us properly, and are started after
DBus, so we can rely on it actually being there. Remove all the useless dead
code for reading the Harmattan session file.