Revert "Bug 676077: Fix handling of Keyboard Input on Windows"

Hi,

From the commit message:

The actual code that does the IM context code handling on Windows now uses the native Windows APIs to handle keystrokes, so this patch is no longer needed, as it was found that it instead caused issues.

Pointed out in issue #2865 (closed).

This reverts commit fd6ce997.

Fixes issue #2865 (closed).

With blessings, thank you!