[qtcontacts-sqlite-extensions] Improve debug logging from TWCSA

This commit adds support for run-time enablement of detailed logging
which, when enabled, causes debug traces to be produced by the
TwoWayContactSyncAdapter code.  The environment variable to enable
the logging is QTCONTACTS_SQLITE_TWCSA_TRACE=1.

src/src.pro

 TEMPLATE = subdirs
 
-SUBDIRS = \
-        engine
+SUBDIRS = engine
+
+OTHER_FILES = \
+    extensions/contactmanagerengine.h \
+    extensions/QContactDeactivated \
+    extensions/qcontactdeactivated.h \
+    extensions/qcontactdeactivated_impl.h \
+    extensions/qcontactincidental_impl.h \
+    extensions/QContactIncidental \
+    extensions/qcontactincidental.h \
+    extensions/qcontactoriginmetadata_impl.h \
+    extensions/QContactOriginMetadata \
+    extensions/qcontactoriginmetadata.h \
+    extensions/qcontactstatusflags_impl.h \
+    extensions/QContactStatusFlags \
+    extensions/qcontactstatusflags.h \
+    extensions/qtcontacts-extensions_manager_impl.h \
+    extensions/qtcontacts-extensions.h \
+    extensions/qtcontacts-extensions_impl.h \
+    extensions/twowaycontactsyncadapter.h \
+    extensions/twowaycontactsyncadapter_impl.h
+