pull up r18836 from trunk

pull up r18836 from trunk

 r18836@cathode-dark-space:  coffman | 2006-11-17 14:48:17 -0500
 subject: update krb5_c_keylength function, create krb5_c_random_to_key function
 ticket: new
 Target_Version: 1.6
 Tags: pullup

 Modify the keylength function to return both keybytes and keylength.
 Change the name of the function and source file to reflect this.

 Add a function, krb5_c_random_to_key() that takes random input data
 of the right length (keybytes) and produce a valid key for a given
 enctype.

ticket: 4799
version_fixed: 1.6

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/krb5-1-6@18890 dc483132-0cff-0310-8789-dd5450dbe970