Protect against rouge asterisks

An asterisk at the end of a phrase ("security engin"*) will cause MySQL to throw an error

An asterisk by itself (this AND \* AND that) will cause MySQL to throw an error

Proposed solution:
Merge asterisk against last word if not an operator

`this * AND that` => `this* AND that`

Otherwise, remove the asterisk altogether 
`this AND * AND that` => `this AND AND that`
