More work on Market functionality and UI

* Now loads all market items.
* Can filter market items.
* Will load market offers on items.
* Edited some UI images.

modules/game_market/ui/general/marketcombobox.otui

@@ -0,0 +1,45 @@
+MarketComboBoxPopupMenuButton < UIButton
+  height: 18
+  font: verdana-11px-antialised
+  text-align: left
+  text-offset: 2 0
+  color: #aaaaaa
+  background-color: alpha
+
+  $hover !disabled:
+    color: #ffffff
+    background-color: #ffffff44
+
+  $disabled:
+    color: #555555
+
+MarketComboBoxPopupMenuSeparator < UIWidget
+  image-source: /images/combobox_rounded.png
+  image-repeated: true
+  image-clip: 1 59 89 1
+  height: 1
+  phantom: true
+
+MarketComboBoxPopupMenu < UIPopupMenu
+  image-source: /images/combobox_rounded.png
+  image-clip: 0 60 89 20
+  image-border: 1
+  image-border-top: 0
+  padding: 1
+
+MarketComboBox < UIComboBox
+  font: verdana-11px-antialised
+  color: #aaaaaa
+  size: 86 20
+  text-offset: 3 0
+  text-align: left
+  image-source: /images/combobox_rounded.png
+  image-border: 1
+  image-border-right: 17
+  image-clip: 0 0 89 20
+
+  $hover !disabled:
+    image-clip: 0 20 89 20
+
+  $on:
+    image-clip: 0 40 89 20