Set krb4 and priocntl flags via site.exp instead of command line

Set krb4 and priocntl flags via site.exp instead of command line

Update set of files to clean out at test suite startup, or when
deleting the database.

Improve support for setting up slave test environment.  Don't set
KRB5_KDC_PROFILE except in KDC master and slave environments.  Create
distinct env.sh and env.csh files for different configurations.  Move
kpropd setup proc into common initialization.

Add incremental propagation test: Create new kiprop/$host principal,
update kproplog test for the new data.  "Propagate" the master
database to the slave, add a new principal, start up kpropd, watch for
the "OK" message, and check to see if the new principal exists on the
slave.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@21134 dc483132-0cff-0310-8789-dd5450dbe970