Generalize the the special handling of HR tags in
goog.editor.range.placeCursorNextTo() to better handle IMG tags and
other no-child-allowed Element nodes. This logic now takes effect
for all browsers, rather than just IE/IE9.
The the original behavior caused scrolling issues
when inserting images or emoji in gmail, on IE.
Also change (for IE) the order in which we set focus and restore
the cursor in abstractDialogPlugin.
This fixes the scroll-to-the-top-after-insert behavior on IE, 
as this new set of calls doesn't spoil the
restoration of the proper scroll position.

R=nicksantos
DELTA=209 (167 added, 18 deleted, 24 changed)


Revision created by MOE tool push_codebase.
MOE_MIGRATION=6062


git-svn-id: http://closure-library.googlecode.com/svn/trunk@2407 0b95b8e8-c90f-11de-9d4f-f947ee5921c8

fix spelling:
nubmer -> number

R=arv
DELTA=1 (0 added, 0 deleted, 1 changed)


Revision created by MOE tool push_codebase.
MOE_MIGRATION=6063


git-svn-id: http://closure-library.googlecode.com/svn/trunk@2408 0b95b8e8-c90f-11de-9d4f-f947ee5921c8