Basic CacheLoader tests

cacheLoader/smoke/dist.bt includes the basic list of tests to run.
Each test runs for about 15 minutes (totalTaskTimeSec = 600).

distNoExp.conf is the simplest config, with no expiration.
The other configs vary cache expiration actions.

- Run the bt file multiple times (at least 5), to exercise various
combinations.

- On a single platform: scale back the numHost variations depending on
the box being used.  A basic Windows box can generally only run the
numHosts=2 configs.  On my Solaris desktop, I comment out the
numHosts=4 config if I am doing anything else on the box.

- On multiple platforms: For remote tests, add something like the
following in local.conf.

//numHosts=2 configs: 
hydra.HostPrms-hostNames         = duck     stealth;

//numHosts=3 configs:
hydra.HostPrms-hostNames         = duck     stealth  biker;

etc.
