Code for transcriber to extract transcribed interval to praat collection

Currently all of the code to do the actual extraction and saving is within the conditional that starts at:

			if trans_node$ == trans_node_extract_snippet$

As noted there, 

#### Issue: As soon as Mary or Pat has the time, this maybe should be rewritten as a call to a proc  
####    that is stored in a separate file, for use in other scripts such as the segmentation script.