Use signtool from Windows Driver Kit 8
Misc fixes.
Merge remote-tracking branch 'origin/master'
Revert "Misc fixes."

This reverts commit 32f6477cdc3fb13ff98f33181cfdcc1a190a8fb1.
Portability fixes.
Silence some misterminated file warnings.
Use the officially-sanctioned method to invalidate a GTK+ window from any thread.
Fix omission of request callback, which was causing null ptr to be returned.
Need to choose a windows version to get threading support.
Add contents scale change event (handles NPNVcontentsScaleFactor).
Remove browser detection which broke on IE11
fix weak_ptr checking in JSObject, wrap InvokeAsync usage in catch
Merge pull request #125 from dougma/FB-253

fix weak_ptr checking in JSObject, wrap InvokeAsync usage in catch
Merge pull request #124 from dougma/FB-252

Remove browser detection which broke on IE11
Merge pull request #119 from gm281/contents-scale-factor-handling

Add contents scale change event (handles NPNVcontentsScaleFactor).
Fix for a crash during shutdown
Merge pull request #126 from abelcher/master

Fix for a crash during shutdown
Merge pull request #111 from adriancrco/master

Use Windows Driver Kit 8 in Windows 8
Merge pull request #117 from michael-fig/master

Getting the hang of things.
fix for FB-254

Just one class registration is sufficient.