[autotest] Continuing refactor of dynamic_suite code; splitting monster files!

Split the biiiiig dynamic_suite.py and dynamic_suite_unittest.py into separate
files for Reimager and Suite.  Adjust imports to compensate.

BUG=chromium-os:30266
TEST=unit
TEST=successful run_suite.py run
TEST=suite_enumerator.py, suite_preprocessor.py,

Change-Id: I0457053a7ae1422970138619a64edbcfbbc338bc
Reviewed-on: https://gerrit.chromium.org/gerrit/30457
Tested-by: Chris Masone <cmasone@chromium.org>
Reviewed-by: Scott Zawalski <scottz@chromium.org>
Commit-Ready: Chris Masone <cmasone@chromium.org>
19 files changed