Imported Upstream version 0.18
Merge tag 'upstream/0.18'

Upstream version 0.18

# gpg: Unterschrift vom Do 11 Apr 2013 21:59:06 CEST mittels RSA-Schlüssel ID E0EA0783
# gpg: Korrekte Unterschrift von "Jan-Hendrik Peters <hennr@hennr.name>"
# gpg:                     alias "Jan-Hendrik (hennr) Peters <hennr@hennr.name>"
add improvised version of changelog for version 0.18