Initial image support

* png: add missing filters, various decoder fixes
* term: fix kitty response interpretation, add support for kitty image
  detection
* buffer, pager: initial image display support

Emphasis on "initial"; it only "works" with kitty output and PNG input.
Also, it's excruciatingly slow, and repaints images way too often.

Left undocumented intentionally it for now, until it actually becomes
useful.  In the meantime, adventurous users can find out themselves why:

[[siteconf]]
url = "https://.*"
images = true

1 files changed, 5 insertions, 1 deletions

diff --git a/src/css/cascade.nim b/src/css/cascade.nim
index 9c3e5803..b2d007f2 100644
--- a/src/css/cascade.nim
+++ b/src/css/cascade.nim
@@ -380,7 +380,11 @@ proc applyRulesFrameInvalid(frame: CascadeFrame; ua, user: CSSStylesheet;
         styledParent.children.add(styledText)
     of peImage:
       let src = Element(styledParent.node).attr(satSrc)
-      let content = CSSContent(t: ContentImage, s: src)
+      let content = CSSContent(
+        t: ContentImage,
+        s: src,
+        bmp: HTMLImageElement(styledParent.node).bitmap
+      )
       let styledText = styledParent.newStyledReplacement(content)
       styledText.pseudo = pseudo
       styledParent.children.add(styledText)