Escape colon ":" in search value.

Hi,

First thanks for the awesome library.

I appreciate your answer might be, not yet implemented, given your recent quest for maintainers, but doesn't hurt to ask :)

Is there a current way to escape delimiters in search values, for example, say I have the following research request

`http://localhost:1337/api/contacts?search=updated_at:2017-02-27+21:58:35.000&searchFields=updated_at:>=`

`RequestCriteria::parserFieldsSearch()` explodes on ":" so the datetime value becomes ` 2017-02-27 21` in the resulting query.

Is there currently a solution to this?

Thanks :)