Added a case that allows packets to be sent by unit of time (in seconds) rather than by number of packets or nal methods. Also made a variable that can be changed in vidgrinder to choose the amount of time, called PsiTime
Chunksize can be calculated without needing an ALSA device instance.
Added a DataSize function to pcm package for calculating size of pcm data given relevant attributes.
Removed ChunkSize from config revid config struct.
Changed NewByteLexer to accept an in rather than a pointer.
av/device/device.go now contains the AVDevice interface and implementations of this
interface, namely, raspivid, geovision, webcam and file are contained in the packages
av/device/raspivid, av/device/geovision, av/device/webcam and av/device/file
respctively. config.go and testing was also moved to a new package called config.go in
order to remove would be circular dependency between AVDevice implementations and revid.
Modifications were made elsewhere expecting config.Config to be part of the revid package.