[Feature]: Add a Field in 3 Simple Steps

This is something I've been dreaming about for a long time, and finally had some time to implement. Next step: integrate with browser, and possible offer as a refactoring… Motivation: Define a descripton on a class, along with instVar, getter and setter, in three easy steps. Example Usage: ```smalltalk MyClass maAddField: #employeeNumber. ``` 1. A list of MADescription subclasses will appear; select one. 2. Next fill out a Morphic Magritte form on a prototype of your selection from #1 3. An annotated description-creation method will be added to MyClass. If you gave the description an MASelectorAccessor, the instVar, getter, and setter will be created if needed. ----- Cheers, Sean -- Sent from: http://forum.world.st/Magritte-Pier-and-Related-Tools-f115649.html