Check if the contents of Object Browser changed
Save the entire contents of the Object Browser in a buffer and compare
it with a backup buffer. Only send a message to Vim telling it to update
the Object Browser if there is any difference between the two buffers.
This makes the option vimcom.alwaysls unnecessary. Previously, there
were two options: always update the object browser or update only when
the total number of objects has changed. The new method may be slower,
but is more precise.