Release 1.3

Several improvements, with many thanks to Jens Lechtenbörger @lechten

Release 1.2.1

This is likely the last release before I retire (on 2016-05-31). I've closed all easily closable issues and included the note that future maintenance of the book will depend on contributions from others.

version 1.2

Lots of little fixes and updates; the biggest change is probably the deletion of obsolete information on web services. Hopefully someone will take the hint to contribute a new version of that section.

version 1.1.6

updated zip file of pdf figures because one was changed in 1.1.6