added get_setting; removed obsolete ISABELLE_HOME, ISABELLE_HOME_USER; added platform_path, which expands variables and performs basic cygwin conversion;
added get_setting;
removed obsolete ISABELLE_HOME, ISABELLE_HOME_USER;
added platform_path, which expands variables and performs basic cygwin conversion;

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle