Fixed a bug in man.lua when help topic wasn't found.

Moved dig.lua to a loot disk.
Added loot disks to creative tab. Won't show in NEI, just classic creative tab, but I'm OK with that.

src/main/resources/assets/opencomputers/loot/loot.properties

@@ -2,3 +2,4 @@
 # Each entry is a mapping of folder name to disk label.
 BetterShell=besh
 OpenIRC=irc
+TheDig=dig

src/main/resources/assets/opencomputers/lua/rom/bin/man.lua

@@ -11,7 +11,7 @@ end
 local topic = args[1]
 for path in string.gmatch(os.getenv("MANPATH"), "[^:]+") do
   path = shell.resolve(fs.concat(path, topic), "man")
-  if fs.exists(path) and not fs.isDirectory(path) then
+  if path and fs.exists(path) and not fs.isDirectory(path) then
     os.execute(os.getenv("PAGER") .. " " .. path)
     os.exit()
   end

src/main/resources/assets/opencomputers/lua/rom/boot/01_os.lua

@@ -7,7 +7,7 @@ local unicode = require("unicode")
 local env = {
   EDITOR="/bin/edit",
   HOME="/home",
-  MANPATH="/usr/man",
+  MANPATH="/usr/man:.",
   PAGER="/bin/more",
   PATH="/bin:/usr/bin:/home/bin:.",
   PS1="# ",

src/main/scala/li/cil/oc/CreativeTab.scala

@@ -8,5 +8,11 @@ object CreativeTab extends CreativeTabs(CreativeTabs.getNextID, "OpenComputers")
   @SideOnly(Side.CLIENT)
   override def getTabIconItemIndex = Settings.get.blockId2
 
+  override def displayAllReleventItems(list: java.util.List[_]) = {
+    def add[T](list: java.util.List[T], value: Any) = list.add(value.asInstanceOf[T])
+    super.displayAllReleventItems(list)
+    Loot.disks.foreach(add(list, _))
+  }
+
   override def getTranslatedTabLabel = getTabLabel
 }