Map chair skill + Hired Merchant fix

Changed map chair bonus healing mechanic to be a player skill, instead of promptly available for all players (healing buff takes place only if the player has the skill). Hired Merchant now properly checks for a space on the inventory before permitting a player to buy an item/bundle. Minor fix with concurrency on MapleStorage.

wz/Skill.wz/000.img.xml

@@ -2713,5 +2713,27 @@
       <int name="timeLimited" value="1"/>
       <int name="disable" value="1"/>
     </imgdir>
+    <imgdir name="0000100">
+      <canvas name="icon" width="32" height="32">
+        <vector name="origin" x="0" y="32"/>
+        <int name="z" value="0"/>
+      </canvas>
+      <canvas name="iconMouseOver" width="32" height="32">
+        <vector name="origin" x="0" y="32"/>
+        <int name="z" value="0"/>
+      </canvas>
+      <canvas name="iconDisabled" width="32" height="32">
+        <vector name="origin" x="0" y="32"/>
+        <int name="z" value="0"/>
+      </canvas>
+      <imgdir name="level">
+        <imgdir name="1">
+          <string name="hs" value="h1"/>
+          <int name="time" value="2100000"/>
+        </imgdir>
+      </imgdir>
+      <int name="disable" value="1"/>
+      <int name="invisible" value="1"/>
+    </imgdir>
   </imgdir>
 </imgdir>