sdbusplus: use shorter type aliases

The sdbusplus headers provide shortened aliases for many types.
Switch to using them to provide better code clarity and shorter
lines.  Possible replacements are for:
  * bus_t
  * exception_t
  * manager_t
  * match_t
  * message_t
  * object_t
  * slot_t

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ic63a70d32f4683e0bd92b625cc36c836aa8395a8
diff --git a/manager.cpp b/manager.cpp
index fad77e6..2c4ee11 100644
--- a/manager.cpp
+++ b/manager.cpp
@@ -40,7 +40,7 @@
 {
     try
     {
-        auto msg = sdbusplus::message::message(m);
+        auto msg = sdbusplus::message_t(m);
         auto& args = *static_cast<Manager::SigArg*>(data);
         sd_bus_message_ref(m);
         auto& mgr = *std::get<0>(args);
@@ -55,7 +55,7 @@
     return 0;
 }
 
-Manager::Manager(sdbusplus::bus::bus&& bus, const char* root) :
+Manager::Manager(sdbusplus::bus_t&& bus, const char* root) :
     ServerObject<ManagerIface>(bus, root), _root(root), _bus(std::move(bus)),
     _manager(_bus, root),
 #ifdef CREATE_ASSOCIATIONS
@@ -100,7 +100,7 @@
 
 void Manager::run(const char* busname)
 {
-    sdbusplus::message::message unusedMsg{nullptr};
+    sdbusplus::message_t unusedMsg{nullptr};
 
     // Run startup events.
     for (auto& group : _events)
@@ -275,7 +275,7 @@
     updateObjects(objs);
 }
 
-void Manager::handleEvent(sdbusplus::message::message& msg, const Event& event,
+void Manager::handleEvent(sdbusplus::message_t& msg, const Event& event,
                           const EventInfo& info)
 {
     auto& actions = std::get<1>(info);