Merged from trunk 6917:6937

   Merged from trunk 6917:6937

   +------------------------------------------------------------------------+
   | 6917     | Autodetect if sandbox is active in order to prevent         |
   | zmedico  | recursive sandbox invocation. Thanks to Brian Harring for   |
   |          | the suggestion.                                             |
   |----------+-------------------------------------------------------------|
   | 6918     | Implement iterkeys on top of __iter__ instead of vice       |
   | zmedico  | versa. Thanks to Brian Harring for the suggestion.          |
   |----------+-------------------------------------------------------------|
   | 6919     | Simplify the implementation of config.__iter__ and also     |
   | zmedico  | implement iterkeys().                                       |
   |----------+-------------------------------------------------------------|
   | 6920     | Clean up config.__getitem__(), get() and setdefault()       |
   | zmedico  | implementions.                                              |
   |----------+-------------------------------------------------------------|
   | 6922     | cache the result of --suffix to reduce testing overhead as  |
   | SpankMan | suggested by Mr_Bones_                                      |
   |----------+-------------------------------------------------------------|
   | 6937     | Make quickpkg print a warning if "bindist" is in RESTRICT.  |
   | zmedico  |                                                             |
   +------------------------------------------------------------------------+

svn path=/main/branches/prefix/; revision=6946