Merge remote-tracking branch 'origin/master' into devel

wiki/src/blueprint/Endless_upgrades.mdwn

wiki/src/blueprint/non-discriminatory_language.mdwn

wiki/src/blueprint/personas.mdwn

wiki/src/blueprint/randomness_seeding.mdwn

wiki/src/blueprint/replace_Pidgin.mdwn

wiki/src/contribute/release_process/thunderbird.mdwn

wiki/src/install/inc/overview.html

wiki/src/support/known_issues.de.po

wiki/src/support/known_issues.es.po

wiki/src/support/known_issues.fa.po

wiki/src/support/known_issues.fr.po

wiki/src/support/known_issues.it.po

wiki/src/support/known_issues.mdwn

wiki/src/support/known_issues.pt.po

wiki/src/upgrade/clone-overview.de.po

wiki/src/upgrade/clone-overview.es.po

wiki/src/upgrade/clone-overview.fa.po

wiki/src/upgrade/clone-overview.fr.po

wiki/src/upgrade/clone-overview.html

wiki/src/upgrade/clone-overview.it.po