Enhance Regression audit log

To help debug issues with regression creation and update,
log outcomes of common operations.
diff --git a/lnt/server/db/fieldchange.py b/lnt/server/db/fieldchange.py
index 4961e6a..7f03ba6 100644
--- a/lnt/server/db/fieldchange.py
+++ b/lnt/server/db/fieldchange.py
@@ -261,8 +261,10 @@
                 active_indicators.append(ri)
                 # Update the default title if needed.
                 rebuild_title(session, ts, regression)
+                logger.info("Updated title of Regression({}) to \"{}\"".format(regression.id, regression.title))
                 return True, regression
-    logger.info("Could not find a partner, creating new Regression for change")
+
     new_reg, new_indicators = new_regression(session, ts, [fc.id])
+    logger.info("Could not find a partner, creating new Regression for change: {}".format(new_reg.title))
     active_indicators.extend(new_indicators)
     return False, new_reg
diff --git a/lnt/server/db/regression.py b/lnt/server/db/regression.py
index 65a7e53..b03c767 100644
--- a/lnt/server/db/regression.py
+++ b/lnt/server/db/regression.py
@@ -5,6 +5,7 @@
 from lnt.server.reporting.analysis import RunInfo
 from lnt.server.ui.util import guess_test_short_name as shortname
 from lnt.testing.util.commands import timed
+from lnt.util import logger
 
 
 class RegressionState:
@@ -55,6 +56,7 @@
         new_ris.append(ri1)
     session.add_all(new_ris)
     rebuild_title(session, ts, regression)
+    logger.info("Creating new Regression: {}".format(regression.title))
     session.commit()
     return regression, new_ris
 
@@ -74,7 +76,9 @@
         title = FMT.format(new_size, ', '.join(sorted(benchmarks)))
         # Crop long titles.
         title = (title[:120] + '...') if len(title) > 120 else title
+        logger.info("Rename Regression: \"{}\" to \"{}\"".format(regression.title, title))
         regression.title = title
+
     return regression