* prompter.c (krb5_prompter_posix): Rewrite to no longer use

	* prompter.c (krb5_prompter_posix): Rewrite to no longer use
	longjmp(), as well as to get a non-buffered stdio stream on stdin
	to avoid passwords staying around in stdio buffers.  This does
	have the side effect of possibly losing pre-buffered input from an
	application that reads from stdin using stdio functions prior to
	calling the prompter, but hopefully those are rare.

ticket: 673
ticket: 680

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@15151 dc483132-0cff-0310-8789-dd5450dbe970