testDataMgr doesn't compute grid extents correctly

[clyne]

The code at line:

VAPOR/test_apps/smokeTests/dataMgrTools.cpp

Line 109 in 928fab0

minExt[i] /= 32.0;

which is intended to produce a smaller domain size, fails in the general case, producing extents that are outside of the valid extents. In particular, the code:

minExt[i] /= 32.0;
maxExt[i] /= 32.0;

if the valid extents, for example, run from 10.0 to 100.0. Both the new min and new max would be less than the valid min.