interface changes to allow :foo style keys

change p() to path() (to avoid concflicts with Data::Printer and to be more clear)
preprocess programs to change `:foo` to `path(q{foo})`
	use `q{}` to avoid compilation error for something like "say ':foo'"
	it's still probably not going to do what you want, but at least it won't blow up
change tsv() and csv() to take values instead of keys
	this is better anyway, as it allows you to put arbitrary expressions in your tab/comma separated output
change help text to reflect new interface