Added setHashQuiet and replaceHashQuiet methods

[adamlukaszczyk]

Your documentation state how to set hash without dispatching hash change event:
https://github.com/millermedeiros/Hasher#setting-hash-value-without-dispatching-changed-signal

I found this really useful, so I added wrappers for setHash and replaceHash methods, which do this out of the box.

Tests, readme, etc. will write if you decide to use my contribution ;)

[millermedeiros]

since it's so easy to create the functions (and already on README) I don't see a reason to add it to hasher itself.. I'll keep it open for a few days/weeks to see if anyone else see the value on it, but I won't merge it for now. thanks for your contribution.

[adamlukaszczyk]

Yes, in README you already have this external method. It wraps "quiet" functionality, so why don't do it in standard way ?