Test cases for reading terrain, monster, and item definitions

- For monster attacks, 'd4' now means '1d4' instead of '0d4', and simple numbers without a 'd' are not accepted
- Pop string path after pushing it in the shop test cases

test/files/terrain/minimal.xml

@@ -0,0 +1,13 @@
+<terrains boes="2.0.0">
+	<terrain id='0'>
+		<name>Test Terrain</name>
+		<pic>0</pic>
+		<map>0</map>
+		<blockage>move</blockage>
+		<trim>none</trim>
+		<arena>0</arena>
+		<special>
+			<type>none</type>
+		</special>
+	</terrain>
+</terrains>