Modifications to the new Close On Exit option:

Modifications to the new Close On Exit option:
 - wording change (required a patch to winctrls.c:radioline())
 - `only on clean exit' is used when an old-style config says `yes',
   on the grounds that it's more generally useful than `always' and
   also we want to map the old default to the new default.

git-svn-id: svn://svn.tartarus.org/sgt/putty@928 cda61777-01e9-0310-a592-d414129be87e