Hyphenation: add custom hyphenation rules (#7746)

The hyphenation of a word can be changed from its default
by long pressing for 3 seconds and selecting 'Hyphenate'.
These overrides are stored in a per-language file, i.e:
koreader/settings/user-German.hyph.

frontend/device/thirdparty.lua

@@ -33,9 +33,7 @@ function M:new(o)
             end
         end
     end
-    if o.is_user_list then
-        logger.info(o:dump())
-    end
+    logger.info(o:dump())
     return o
 end
 
@@ -56,7 +54,7 @@ function M:checkMethod(role, method)
 end
 
 function M:dump()
-    local str = "user defined thirdparty apps\n"
+    local str = (self.is_user_list and "user" or "platform") .. " thirdparty apps\n"
     for i, role in ipairs(roles) do
         local apps = self[role.."s"]
         for index, _ in ipairs(apps or {}) do