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/apps/reader/readerui.lua

@@ -48,6 +48,7 @@ local ReaderStyleTweak = require("apps/reader/modules/readerstyletweak")
 local ReaderToc = require("apps/reader/modules/readertoc")
 local ReaderTypeset = require("apps/reader/modules/readertypeset")
 local ReaderTypography = require("apps/reader/modules/readertypography")
+local ReaderUserHyph = require("apps/reader/modules/readeruserhyph")
 local ReaderView = require("apps/reader/modules/readerview")
 local ReaderWikipedia = require("apps/reader/modules/readerwikipedia")
 local ReaderZooming = require("apps/reader/modules/readerzooming")
@@ -314,6 +315,12 @@ function ReaderUI:init()
             view = self.view,
             ui = self
         })
+        -- user hyphenation (must be registered before typography)
+        self:registerModule("userhyph", ReaderUserHyph:new{
+            dialog = self.dialog,
+            view = self.view,
+            ui = self
+        })
         -- typography menu (replaces previous hyphenation menu / ReaderHyphenation)
         self:registerModule("typography", ReaderTypography:new{
             dialog = self.dialog,