bump_crengine: various fixes, tweaks and cleanups (#6188)

Includes:
- Don't reset invisible BR to display: inline
- ldomTextCollector: handle inline-block/table as inline
- Avoid re-rendering on font hinting mode change
- List markers: fix positionning when floats involved
- GIF decoding: avoid uneeded abort on LZW table overflow
- Adds getUnknownEntities(), can help with debugging
- Don't check stylesheet hashes when loading from cache
- Hardcoded elements and attributes list: cleanup
- Full rendering: 2 small optimisations
- Strut confinning: deal with images earlier
- lvtextfm: some cleanup and reordering
cre.cpp:
- fix getPageFromXPointer() and getPosFromXPointer()
  to not fail on invisible nodes and work on the next
  visible node (so links whose target is display:none
  can work).

Add support for 2 settings one can set manually
in reader.settings.reader.lua:
["cre_background_color"] = "0xccffcc",
["cre_background_image"] = "/path/to/bg_paper.jpg",

frontend/document/credocument.lua

@@ -205,6 +205,14 @@ function CreDocument:setupDefaultView()
         self._document:setIntProperty("crengine.page.header.font.size",
             G_reader_settings:readSetting("cre_header_status_font_size"))
     end
+
+    -- One can set these to change from white background
+    if G_reader_settings:readSetting("cre_background_color") then
+        self:setBackgroundColor(G_reader_settings:readSetting("cre_background_color"))
+    end
+    if G_reader_settings:readSetting("cre_background_image") then
+        self:setBackgroundImage(G_reader_settings:readSetting("cre_background_image"))
+    end
 end
 
 function CreDocument:loadDocument(full_document)
@@ -893,6 +901,11 @@ function CreDocument:setStatusLineProp(prop)
     self._document:setStringProperty("window.status.line", prop)
 end
 
+function CreDocument:setBackgroundColor(bgcolor) -- use nil to set to white
+    logger.dbg("CreDocument: set background color", bgcolor)
+    self._document:setBackgroundColor(bgcolor)
+end
+
 function CreDocument:setBackgroundImage(img_path) -- use nil to unset
     logger.dbg("CreDocument: set background image", img_path)
     self._document:setBackgroundImage(img_path)
@@ -941,6 +954,10 @@ function CreDocument:getStatistics()
     return self._document:getStatistics()
 end
 
+function CreDocument:getUnknownEntities()
+    return self._document:getUnknownEntities()
+end
+
 function CreDocument:canHaveAlternativeToc()
     return true
 end