rpcrt4: Check there is enough space in the buffer and that the size doesn't cause an overflow when copying data to it.

Rename safe_buffer_copy to safe_copy_from_buffer.

OpenGL drivers do not support some low precision internal formats
like GL_RGB5 for fbo color targets. Direct3D application depend on them,
so provide a fallback format for render targets if the requested format
itself is not supported.

The surface_blt_to_drawable function changes the filtering settings of
the texture object, but without informing the container about this
change. This patch makes sure that the basetexture knows about this and
reapplies the changed states to the settings chosen by the app.

advapi32: Make the credential registry key stay around if a persist value longer than session is specified.

advapi32: Use the open_for_write parameter to open_cred_mgr_key and fix get_cred_mgr_encryption_key to not need KEY_WRITE access to the key passed in.

Fix memory leaks caused by the variable and interface custom data not 
being freed properly.

Since the code is inside the loop for function data, it should be 
freeing the function's custom data, not the interface's.

It isn't tracked per connection, unlike NTLM authentication, and so the 
server will return a 401 error and try to get us to authenticate again. 
However, this doesn't work as the authentication information is assumed 
by the code to be valid for the whole connection.

It is different to the other base types as it has a different size on 
the wire to in memory, so it can't just be set to the buffer when 
unmarshalling.