last is immutable error and ability to pass in no search parameters.

There are 2 fixes here:
1) We had the problem that an html5 module was setting last, so this update kept the 2 working together.  This may or may not be a good update to pull, your choice.  
2) If we made the search params dynamic and nothing was passed in, we'd error out on null with a call to the desk servers.  This makes search able to accept null params without failing and returning the results as expected.