Update v4l.c method for passing Tensor into c lib

It was using a deprecated torch function call which was generating a warning.
Move v4l open video device code into function

First step in breaking up the camera init function into more manageable
sections.
Have v4l init function return bool value

This is used as an indicator of success in the initiation of the device.
Move v4l capability code into function

Conceptually breaking up the init function.
Move v4l frame format code into function

Code sets the format of the frame with new height/width and pixel types etc.
Move v4l camera control settings into function

This moves the code that sets the frame rate and the initial auto focus and
white balance into a function for clarity.
Move v4l camera buffer init code into function

The camera driver needs buffers to save the images in. This code setups the
buffers ready for use and memory maps them.
Move v4l code to start capturing into function
Consolidate v4l camera init into 1 wrapper function

A convenience. Its internals are still split for ease of reading.
Reorder code & update comments in v4l init function

For clarity.
Add return true/false for grabFrame function

The will inform the caller if there was a problem.
Add more meaningful stride name in v4l grabFrame
Move v4l RGB frame copy into it own function

For clarity.
Replace tab indent with spaces
Merge pull request #18 from bmartini/v4l-code-cleanup

V4l code cleanup