RCP: X.X, move word property selection from dialog box to result editor

Currently, when AFC, CAH and Specificity commands start from a partition a dialog box pops up to ask for the word property name to use to build frequencies.

To align with the Index / Lexicon GUI scenario, we should move the word property name selection into the results editor internal toolbar of the various commands.

(from redmine: issue id 1977, created on 2016/12/20 by Serge Heiden)