PDF written highlights: fix boxes, trash cached tiles

TileCacheItem: add created_ts property.
Document: manage a tile_cache_validity_ts and ignore
older cached tiles.
This timestamps is updated when highlights are written
as annotations in, or deleted from, the PDF, so we can
get the most current rendered bitmap from MuPDF and
avoid highlight ghosts on old tiles.
Save this timestamp in doc settings so older cached to
disk tiles will also be ignored across re-openings.
Bump base for: mupdf.lua: update frontend pboxes with
MuPDF adjusted ones.

frontend/document/pdfdocument.lua

@@ -208,6 +208,20 @@ local function _quadpointsFromPboxes(pboxes)
     return quadpoints, n
 end
 
+local function _quadpointsToPboxes(quadpoints, n)
+    -- reverse of previous function
+    local pboxes = {}
+    for i=1, n do
+        table.insert(pboxes, {
+            x = quadpoints[8*i-4],
+            y = quadpoints[8*i-3],
+            w = quadpoints[8*i-6] - quadpoints[8*i-4],
+            h = quadpoints[8*i-5] - quadpoints[8*i-3],
+        })
+    end
+    return pboxes
+end
+
 function PdfDocument:saveHighlight(pageno, item)
     local can_write = self:_checkIfWritable()
     if can_write ~= true then return can_write end
@@ -223,8 +237,12 @@ function PdfDocument:saveHighlight(pageno, item)
     elseif item.drawer == "strikeout" then
         annot_type = C.PDF_ANNOT_STRIKEOUT
     end
-    page:addMarkupAnnotation(quadpoints, n, annot_type)
+    page:addMarkupAnnotation(quadpoints, n, annot_type) -- may update/adjust quadpoints
+    -- Update pboxes with the possibly adjusted coordinates (this will have it updated
+    -- in self.view.highlight.saved[page])
+    item.pboxes = _quadpointsToPboxes(quadpoints, n)
     page:close()
+    self:resetTileCacheValidity()
 end
 
 function PdfDocument:deleteHighlight(pageno, item)
@@ -237,6 +255,7 @@ function PdfDocument:deleteHighlight(pageno, item)
     local annot = page:getMarkupAnnotation(quadpoints, n)
     if annot ~= nil then
         page:deleteMarkupAnnotation(annot)
+        self:resetTileCacheValidity()
     end
     page:close()
 end
@@ -251,6 +270,7 @@ function PdfDocument:updateHighlightContents(pageno, item, contents)
     local annot = page:getMarkupAnnotation(quadpoints, n)
     if annot ~= nil then
         page:updateMarkupAnnotation(annot, contents)
+        self:resetTileCacheValidity()
     end
     page:close()
 end