Rename ct_c.* to ct_c.*.in. ct_c.sed.in is now processed by sed to

Rename ct_c.* to ct_c.*.in.  ct_c.sed.in is now processed by sed to
remove comment lines beginning with '#', since some sed programs can't
handle that.  Change config_script so that the directory where the
ct_c.* files can be specified, since those are in the build directory,
instead of the source directory.  (This is all for the sake of System
V sed.  Sigh.)

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@6186 dc483132-0cff-0310-8789-dd5450dbe970