build AppImage with Ubuntu 14.04 and Qt 5.9.3

Revert all experimental changes

update translations

Revert changes to build AppImage with Qt 5.9.8

Update version to 3.2 in plugins documentation

fix .yml syntax

Merge pull request musescore#5056 from MarcSabatella/289548-articulat…

…ion-direction

fix #289548: incorrect initial layout of added articulations

fix cmake syntax

update translations

make stable release 3.0.5

Stop pushing strings to Transifex

update translations