(compile-file src)
(compile-file src dest)
(compile-file src dest opts)
Compiles src to a file of the same name, but with a .js extension,
in the src file's directory.
With dest argument, write file to provided location. If the dest
argument is a file outside the source tree, missing parent
directories will be created. The src file will only be compiled if
the dest file has an older modification time.
Both src and dest may be either a String or a File.
Returns a map containing {:ns .. :provides .. :requires .. :file ..}.
If the file was not compiled returns only {:file ...}