layout: do not generate anonymous inline boxes

Anonymous inline boxes were blocking progress on layout caching, so they
are now gone.  Instead, we handle them in layoutInline (which meanwhile
has spaghettified to beyond comprehension...  now it's a special case
of inner BlockBox (kind of?) - incredibly, it still passes tests :P)

This seems to match what major browsers do as well; some test cases were
updated to reflect the "improved" rendering this brings.

Next I'd like to remove anonymous table boxes by generating them in
cascade.  Then it should be straightforward enough to at least reuse
flow roots on relayout.

(And clean up flow layout...)

1 files changed, 3 insertions, 0 deletions

diff --git a/test/layout/center-in-inline.expected b/test/layout/center-in-inline.expected
new file mode 100644
index 00000000..cb132683
--- /dev/null
+++ b/test/layout/center-in-inline.expected
@@ -0,0 +1,3 @@
+                                      test
+                                      test
+                                     test