SQLDatabaseManager optimizations, async profile loading -t00thpick1, zreed

This commit changes our shared connection into a connection pool utility to prevent
thread locks from multiple actions attempting to access the database at the same time.
In additon,  profile loading has been moved off the main thread at login time, to
allieviate the performance issues caused by it.

Fixes #2138, Fixes #2119, Fixes #1982, Fixes #1953

src/main/resources/config.yml

@@ -10,6 +10,8 @@
 General:
     Locale: en_US
     MOTD_Enabled: true
+    # Send a message to the player when his profile was successfully loaded
+    Show_Profile_Loaded: false
     # Amount of time (in minutes) to wait between saves of player information
     Save_Interval: 10
     # Allow mcMMO to report on basic anonymous usage
@@ -122,6 +124,12 @@ MySQL:
         User_Password: UserPassword
         Name: DataBaseName
         TablePrefix: mcmmo_
+        # This setting is the max simultaneous mysql connections allowed at a time, needs to be
+        # high enough to support multiple player logins in quick succession
+        MaxConnections: 30
+        # This setting is the max size of the pool of cached connections that we hold available
+        # at any given time
+        MaxPoolSize: 20
     Server:
         Port: 3306
         Address: localhost