android: allow overrides on 3rd party dictionary list

frontend/device/android/dictionaries.lua

@@ -1,8 +1,11 @@
-return { --[[ supported android dictionary applications.
-
-Most of them should support Intent.ACTION_SEND, Intent.ACTION_SEARCH or
-Intent.ACTION_PROCESS_TEXT. Some applications implement their custom intents. ]]--
+local user_path = require("datastorage"):getDataDir() .. "/dictionaries.lua"
+local ok, dicts = pcall(dofile, user_path)
 
+if ok then
+    return dicts
+else
+    return {
+        -- tested dictionary applications
         { "Aard2", "Aard2", false, "itkach.aard2", "aard2" },
         { "Alpus", "Alpus", false, "com.ngcomputing.fora.android", "search" },
         { "ColorDict", "ColorDict", false, "com.socialnmobile.colordict", "colordict" },
@@ -13,3 +16,4 @@ Intent.ACTION_PROCESS_TEXT. Some applications implement their custom intents. ]]
         { "Mdict", "Mdict", false, "cn.mdict", "send" },
         { "QuickDic", "QuickDic", false, "de.reimardoeffinger.quickdic", "quickdic" },
     }
+end