Merge changes I23e4f19f,I2eb64e18,Ia8f1ca47,I9090d834 into stable-3.6

* changes:
  Migrate gr-diff-highlight from PolymerElement to plain class
  Simplify and clean up gr-diff-highlight
  Migrate gr-diff-highlight_test from js to ts
  Migrate gr-diff-selection from PolymerElement to plain class
diff --git a/modules/jgit b/modules/jgit
index d73b7cd..e982de3 160000
--- a/modules/jgit
+++ b/modules/jgit
@@ -1 +1 @@
-Subproject commit d73b7cdeb4eaf32e3d41c105b974e620b33a168e
+Subproject commit e982de3fcb9f3a2e5ec6ceaae44cbb344962ea01