more uniform signature for various process invocations;
env refers to full environment, not the update;

tuned signature;

updated headers;

clarified ISABELLE_ROOT (platform path) vs. ISABELLE_HOME (standard path);

uniform treatment of bootstrap directories;
Isabelle_System.init() includes Cygwin.init(), e.g. for situations without isabelle.Main;
tuned;

clarified Isabelle_System.init;
clarified GUI.init_laf;
clarified modules;
tuned signature;

Scala version of init.bat;

--HG--
rename : src/Pure/System/cygwin.scala => src/Pure/System/cygwin_init.scala

some support for Cygwin;

discontinued obsolete Cygwin module;

eliminated unused Cygwin download;

simplified Cygwin root: warm start via env, cold start via property, no registry magic;

--HG--
extra : rebase_source : 771d7781373f5e71e6935ec987e6d559ee639e8e

support Cygwin cold-start via Isabelle.exe, assuming layout of bundle;

separate compilation of PIDE vs. Pure sources, which enables independent Scala library;

explicit indication of modules for independent Scala library;

imitate exception ERROR of Isabelle/ML;

explicit import java.lang.System to prevent odd scope problems;

Cygwin: Poly/ML 5.4.0 requires libgmp3;

tuned signatures and messages;

eliminated hard tabs;

THIS_CYGWIN;

Standard_System.raw_exec;
more robust root.mkdirs;

added Cygwin "make" package;

tuned error handling;

Standard_System.raw_execute: optional cwd;
basic Cygwin.setup with download and unattended installation;

crude Cygwin.setup;

simplified Cygwin setup, assuming 1.7 registry layout (version 1.5 suffers from upcaseenv problem anyway);

more robust Cygwin.config: actually check Wow6432Node, prefer explicit CYGWIN_ROOT in any case;

fixed permissions;

some more Cygwin checks;

Accessing the Cygwin installation.