[autotest] Move dynamic suite code into its own module

No big rewrite, just moving files around

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

Change-Id: I2fbcae0332104ce3adcb10a1e90ce94cb209aca8
Reviewed-on: https://gerrit.chromium.org/gerrit/30267
Reviewed-by: Scott Zawalski <scottz@chromium.org>
Commit-Ready: Chris Masone <cmasone@chromium.org>
Tested-by: Chris Masone <cmasone@chromium.org>

client/common_lib/error.py

diff --git a/client/common_lib/error.py b/client/common_lib/error.py
index c6febba..42a0875 100644
--- a/client/common_lib/error.py
+++ b/client/common_lib/error.py
@@ -498,7 +498,8 @@
 
 class CrosDynamicSuiteException(Exception):
     """
-    Base class for exceptions coming from dynamic suite code in server/cros/*.
+    Base class for exceptions coming from dynamic suite code in
+    server/cros/dynamic_suite/*.
     """
     pass