VisualUnitTest: Check for -d flag before handling dir clean up
VisualUnitTest: Check for -d flag before handling dir clean up

By checking for passage of the -d flag -- disable image set
comparisons -- we save a bit of exec time and remove err logging
that is not relevant to our current test configuration, i.e.:
"ERROR: [ UnixFile.cpp : 220 ] Could not read directory path:
  /Users/jeff/Documents/nomlib/tests/ActionTest/ActionTest_<timestamp>"

* The test output directory path is now only set && created when -d
has not been passed.
* Remove redundant 'image set comparison is disabled' logging in
::initialize_directories (already done in ::compare).

i8degrees/nomlib,i8degrees/nomlib,i8degrees/nomlib,i8degrees/nomlib