Added tag 3.2.1 for changeset e4ce9b6392fe
Bumped to 3.2.2 in preparation for next release.
Addtional check to detect whether KDE is used

It seems not all KDE releases (or distros) set the KDE_SESSION_ID enviroment
variable. Added a check for KDE_FULL_SESSION which seems to be used more
widely.
Use set intersection instead of a sequence of 'not in' tests.
Update changelog