include: Make the return type of mmioSendMessage16 in the function declaration match that of the function definition.

msi: Adds test to check "JOIN" operator with "*" operator for the SELECT clause returns the correct results.

msi: Adds test to check if basic "JOIN" operator without "WHERE" clause returns the correct results.

gdi32: GetTextExtentPoint and GetTextExtentExPoint behave differently if there's a \n in the string.

msi: Use ACTION_UpdateComponentStates in the selection tree so we don't have to duplicate the component changing logic.