Fix a bunch of warnings

using the list of warnings from here:
https://github.com/lefticus/cppbestpractices/blob/e73393f25a85f83fed7399d8b65cb117d00b2231/02-Use_the_Tools_Available.md#L100

Seems like a good place to start, and would improve things a bit
type-wise.  This patchset attempts to correct all the issues in one
shot.

Tested:
It builds.  Will test various subsystems that have been touched

Signed-off-by: Ed Tanous <ed.tanous@intel.com>
Change-Id: I588c26440e5a97f718a0f0ea74cc84107d53aa1e
diff --git a/redfish-core/lib/message_registries.hpp b/redfish-core/lib/message_registries.hpp
index ef443af..96ce0c2 100644
--- a/redfish-core/lib/message_registries.hpp
+++ b/redfish-core/lib/message_registries.hpp
@@ -257,7 +257,7 @@
             if (message.second.numberOfArgs > 0)
             {
                 nlohmann::json &messageParamArray = obj["ParamTypes"];
-                for (int i = 0; i < message.second.numberOfArgs; i++)
+                for (size_t i = 0; i < message.second.numberOfArgs; i++)
                 {
                     messageParamArray.push_back(message.second.paramTypes[i]);
                 }