Core/Movement: Port Ascent r1637 http://sourceforge.net/p/ascentemubackup/code/1637/ to TrinityCore

Port some movement packet fixes, taking into account client/server connection lag.
Credits to original author, check http://sourceforge.net/p/ascentemubackup/code/1637/ for more details.
MOVEMENT_PACKET_TIME_DELAY default value is currently set to 0, feel free to set it to different values and report feedback.

src/server/game/Server/WorldSession.cpp

@@ -115,6 +115,7 @@ WorldSession::WorldSession(uint32 id, WorldSocket* sock, AccountTypes sec, uint8
     m_sessionDbcLocale(sWorld->GetAvailableDbcLocale(locale)),
     m_sessionDbLocaleIndex(locale),
     m_latency(0),
+    m_clientTimeDelay(0),
     m_TutorialsChanged(false),
     recruiterId(recruiter),
     isRecruiter(isARecruiter),