[add new options dealing with the ho cache, ho dir, and a routine to just check dependencies.
John Meacham <john@repetae.net>**20080212071256] hunk ./Main.hs 115
+        DependencyTree -> doDependency (optArgs o)
hunk ./Options.hs 51
+          | DependencyTree -- ^ show simple dependency tree
hunk ./Options.hs 70
+    optHoDir       ::  Maybe FilePath,
+    optHoCache     ::  Maybe FilePath,
hunk ./Options.hs 101
+    optHoDir       = Nothing,
+    optHoCache     = Nothing,
hunk ./Options.hs 158
+    , Option []    ["ho-cache"]    (ReqArg (optHoCache_s . Just ) "HOCACHEDIR")    "Use a global ho cache located at the argument"
+    , Option []    ["ho-dir"]      (ReqArg (optHoDir_s . Just ) "<dir>")    "Where to place and look for ho files"
+    , Option []    ["dependency"]  (NoArg  (optMode_s DependencyTree))  "Follow import dependencies only then quit"