rfc: selectable to be radiable

After a brief discussion on IRC, it was suggested that 'selectable' was 
a misleading term for the mutually exclusive selection behaviour widget.

For instance, a <check/> is selectable as in you say 'selected=true', 
but it doesn't apply selectable.

<JeffBuhrt> 'mutually exclusive selection' implies radi. The abstract 
meaning then maybe is what needs  better defined.

So, how about it?  Should 'selectable' actually be 'radiable'?

That was the most popular option in the chat.

Other options:

  o  electable - well, it's not really an election
  o  peggable - er, not sure where it came from
  o  pickable - you do pick one :)
  o  radioable - more difficult to say

Any compelling arguments for or against, or any other suggestions?

- Charlie