Remove the -re flag, as it makes low frame rate CBR video drop frames

[tstordyallison]

Dependent on #10, so best wait for that to land first before reviewing!

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Remove the -re flag, as it makes low frame rate CBR video drop frames all over the place. ffmpeg knows better!

• added 'debugFfmpeg' option to chill the logs.
• other tidy up as we go and some TODOs for later.

[sponte]

Thanks for the contribution, merging and will release as 1.0.13