More read/write test cases for monsters, especially monster abilities

Fixes:
- For radiate abilities, the pattern was not saved and defaulted to single instead of square on load
- For summon abilities, what to summon was not saved and chance was incorrectly saved

test/files/monsters/abil_radiate/pattern.xml

@@ -0,0 +1,22 @@
+<monsters boes="2.0.0">
+	<monster id='1'>
+		<name>Test Monster</name>
+		<level>1</level>
+		<armor>0</armor>
+		<skill>2</skill>
+		<hp>10</hp>
+		<speed>4</speed>
+		<race>humanoid</race>
+		<attacks/>
+		<pic h='1' w='1'>5</pic>
+		<attitude>hostile-a</attitude>
+		<immunity/>
+		<abilities>
+			<radiate type='radiate'>
+				<type>cloud-sleep</type>
+				<pattern>plus</pattern>
+				<chance>75</chance>
+			</radiate>
+		</abilities>
+	</monster>
+</monsters>