Scala version of "isabelle doc";
discontinued slightly odd / unused ">>" comments within Contents (see also b077b79061b6);

Isabelle-hg: http://isabelle.in.tum.de/repos/isabelle@52427 9d1cc9a22177cdb10d0e8a3cbe11c1f605044fc5
clones of increase-font-size / decrease-font-size to allow two further shortcuts for various keyboard layouts;

Isabelle-hg: http://isabelle.in.tum.de/repos/isabelle@52428 fce1c133e1f8330e8679652494098df576e3ad45
detach process more reliably -- NB: viewer might be synchronous or asynchronous depending on settings;

Isabelle-hg: http://isabelle.in.tum.de/repos/isabelle@52429 921f22c8890ebcf1872b19af675c905ae3ef921e