test-clip: Do not set black/silent by default
audiotransition: Fix porting error of the interpollator

  + update debug statements s/LOG/INFO

(acontrolsource != bcontrolsource)
audiotransition: Add a resampler in the audio transition bin
video-test-src: Force video/x-raw

Avoiding to hit errors with video/x-bayer
timeline-pipeline: Copy the caps so they are writable.
Add a basic rendering test.
Add more simple test cases, two of them not working for now (transitions and effects)
Test-utils: Add test file generation code.
test-render: Use testfile generation, and set us up for debugging transitions with ogg.
tests: render: Update test suite, split tests.

	+ free strings.
	+ basis for an element based dot dump.