[Pharo-dev] please test: Make Spec use RubPluggableTextMorph instead of PluggableTextMorph

https://pharo.fogbugz.com/default.asp?15774 Like that we can get rid of the bug https://pharo.fogbugz.com/default.asp?15773 where SHRB is doing wrong semantic analysis and this is one less ref to PluggableTextMorph. We are trying to get rid of it by either using RubPluggableTextMorph or and better RubScrolledTextModel Stef