LOCCR is a Lines of Code Counter in Rust.
It recursively searches a directory for files with a given extension, counting lines.
A new task is spawned for each sub-directory found
   (not necessarily helpful because counting lines is mostly io-bound, but testing tasks is fun)

Testing:
	Compare
		`./loccr test txt`
	with
		`find test -name "*.txt" | xargs wc -l`

Todo:
  Add language-specific filters for finding comments and such.