Handle assignments in 'switch' conditions.

This simply uses the same pattern for handling conditions in 'while',
'if', and so on. 'this.condition' is no longer set. It's not used
at the moment, so nothing should break.

Fixes #1018
Add test for GH-1018.
Merge branch 'assignment-in-switch-condition' of git://github.com/usrbincc/jshint into usrbincc-assignment-in-switch-condition

Conflicts:
	tests/stable/unit/parser.js
Fixed lint erros introduced in the USERPROFILE patch