Merge tag '0.20.1'

.travis.yml

README.md

appveyor.yml

ci/appveyor/after_install.cmd

ci/appveyor/sakia.iss

ci/travis/after_success.sh

ci/travis/before_deploy.sh

ci/travis/before_install.sh

ci/travis/build.sh

ci/travis/debian/DEBIAN/control

ci/travis/debian/DEBIAN/postinst

ci/travis/debian/DEBIAN/prerm

ci/travis/debian/usr/share/applications/sakia.desktop

ci/travis/qt-installer-noninteractive.qs

ci/travis/test.sh

doc/uml/api.png

doc/uml/core-classes.png

doc/uml/core-classes.pu

doc/uml/cutecoin.png

doc/uml/gui-classes.png