Major re-arrangement of eddy tests

so that job submission / monitoring code is shared across all tests in a common runEddy script. Also test both $FSLDIR/bin/eddy_openmp and $FSLDIR/bin/eddy_cpu if either exist. Tests can be executed either on a cluster submission node, or locally

eddy/feedsInputs

+EddyTestData/eddyData
+EddyLSRTestData/eddyData
+EddyMBSTestData/eddyData
+EddyS2VTestData/eddyData
+EddyHigh_b_TestData/eddyData