Add not-equal operator to Crowd Query Language

The documentation in https://developer.atlassian.com/server/crowd/crowd-query-language tells us that we have 3 operators to use on a search request using CQL:

• Equal (=)
• Greater than (>)
• Less than (<)

Using the API, we can query for an e-mail containing bob:

email=*bob*

But we can't query for e-mails that don't contain bob.