update LuaDocs for Classes

Fix, clarify, and expand prose in LuaDocumentation.xml for classes made
available to Lua.

Add elements for DeviceList, InputList, Quad, and SongMeterDisplay to
Lua.xml.

Docs/Luadoc/Lua.xml

@@ -783,6 +783,8 @@
 			<Function name='get_dirty'/>
 			<Function name='destroy'/>
 		</Class>
+		<Class base='BitmapText' name='DeviceList'>
+		</Class>
 		<Class name='DisplayMode'>
 			<Function name='GetWidth'/>
 			<Function name='GetHeight'/>
@@ -1044,6 +1046,8 @@
 			<Function name='GetMouseX'/>
 			<Function name='GetMouseY'/>
 		</Class>
+		<Class base='BitmapText' name='InputList'>
+		</Class>
 		<Class base='ActorFrame' name='LifeMeter'>
 			<Function name='GetLife'/>
 			<Function name='IsFailing'/>
@@ -1534,6 +1538,8 @@
 			<Function name='SaveProfile'/>
 			<Function name='SetStatsPrefix'/>
 		</Class>
+		<Class base='Sprite' name='Quad'>
+		</Class>
 		<Class name='RadarValues'>
 			<Function name='GetValue'/>
 		</Class>
@@ -1870,6 +1876,8 @@
 			<Function name='WasLoadedFromAdditionalCourses'/>
 			<Function name='WasLoadedFromAdditionalSongs'/>
 		</Class>
+		<Class base='MeterDisplay' name='SongMeterDisplay'>
+		</Class>
 		<Class name='SongOptions'>
 			<Function name='AssistClap'/>
 			<Function name='AssistMetronome'/>