The RichEditWndProc_common function is big enough already by handling
all the window messages, so moving code to handle a message to its own
function makes the code more readable.

Adds a binary resource that consists of the string "Wine placeholder
BINK resource" padded with zeroes.

Spotted by Andrew Talbot.

Also corrects some related comments.

Based on a patch by Maarten Lankhorst.

d3d8: Use the wined3d declaration to retrieve the d3d8 shader in IDirect3DDevice8Impl_GetVertexShader().

This makes it no longer necessary to create a wined3d vertex shader
when the d3d8 vertex shader has a NULL function.