discontinued "isabelle usedir" option -r (reset session path);
simplified internal session identification: chapter / name;
clarified chapter index (of sessions) vs. session index (of theories);
discontinued "up" links, for improved modularity also wrt. partial browser_info (users can use "back" within the browser);
removed obsolete session parent_path;
syntax: glob
*~
*.class
*.jar
*.orig
*.rej
.DS_Store
syntax: regexp
^contrib
^heaps/
^browser_info/
^doc/.*\.dvi
^doc/.*\.eps
^doc/.*\.pdf
^doc/.*\.ps
^src/Tools/jEdit/dist/