clarified module dependencies: avoid Properties and Document introding minimal "PIDE";

Isabelle-hg: http://isabelle.in.tum.de/repos/isabelle@51818 517f232e867d4f01870a20c57bcdc266e925327c
cygwin_root as optional argument;
tuned;

Isabelle-hg: http://isabelle.in.tum.de/repos/isabelle@51820 142c69695785cb357c56f527e7927e86d32afb8c