3.4.3

This release now requires Grease >1.6

Bugfixes:

(see issue descriptions for more detail)
#1211: Multiple value Headers only set the latest one when converting a WAResponse to ZnResponse (thanks @eMaringolo!)
#1205: WADevelopmentFiles svg files were still in binary format and thus failed to load in the halos development visuals
#1214: New control panel in Pharo8+ based on Spec2 (thanks @jecisc!)