shell-recorder-src: only negotiate once

Set the format of the basesrc to the configured caps only once
during negotiation instead of before pushing each buffer.
shell-recorder-src: use timestamping from basesrc

Use the do-timestamp feature of basesrc to place the correct timestamp
on each outgoing buffer.
shell-recorder-src: allow sending EOS to our source

When we send EOS to our source, make it queue the special item to cause
EOS after all buffers are pushed.
shell-recorder: depth and bpp are no more in 1.0

Remove 0.10 style bpp and depth, they are not needed anymore, the
format specifies the layout completely.
shell-recorder: send EOS to the pipeline

Send EOS to the complete pipeline instead of only to our own source.

When there are multiple sources in the pipeline (for example when we also
record audio), the pipeline will send the EOS to all sources in order to
shut down the complete pipeline.
DBus: Remove flash argument

There is no flash argument implemented.