parametrize the quote environment to use in latex output

The LaTeX quote environment is very limited (as is the quotation environment), and I needed to use the quoting package to avoid horizontal white space in a line-by-line transcription.  The quoting package is the most flexible, so using it unconditionally may be an option, but then its parameters need to be configurable, and also its auto-detection is currently not compatible with the generated output (it seems to use whitespace instead of not \par, etc).  I don't know much about the whole topic to even try a fancy solution, so I offer this easy parametrization for a first step.  The whole quote-business seems to be somewhat messy, and LaTeX quote environments are currently overloaded for different use cases.  Oh well!