Make automated test from example

[ilectra]

Starting from the Test_hmc_Sp_WilsonFundFermionGauge example, build something that does automated (regression) testing.

For coarse-grained approximate regression testing, pull out the value of the plaquette that is output (grep Plaquette), for an exact comparison. For a more precise test, you can save the final configuration and compare that - set CPparams.saveInterval = 1 rather than the default 100.

DONE:

• local script in tests/sp2n that does our testing only? OR
• some general framework for GRID, to be contributed upstream? Check first what's already there - if anything