Release 0.12: closed "Changes Since ..." section

change version number to 0.11

add a reminder fpr 0.12

Release 0.10: set version number to 0.10

Release 0.9.1: set version number to 0.9.1

Release 0.9: set version number to 0.9

Release 0.8.1: closed "Changes Since ..." section

Release 0.8: closed "Changes Since ..." section

some more changes in 0.7

Release 0.6: closed "Changes Since ..." section

Release 0.5: closed "Changes Since ..." section