Support NumberFormat#multipleOf

[georgewfraser]

http://json-schema.org/latest/json-schema-validation.html#anchor14

[cowtowncoder]

Sounds good, would be happy to merge this. Since it's an API change, it needs to go in 2.7, and I just upgrade master to that.

One practical thing we need before merge is the Contributor License Agreement (CLA). Unless I have asked and gotten one earlier (apologies if so -- I tried to check archives), it is needed once, and then I can merge all contributions.

The usual way is to download CLA from https://github.com/FasterXML/jackson/blob/master/contributor-agreement.pdf, print it, fill & sign, scan and email to info at fasterxml dot com.
Apologies for this extra step, but corporate users are quite strict in checking projects follow basic guidelines for contributions, and this is the simplest workflow we could think of.

Once again for this and other contributions, looking forward to merging them!

[georgewfraser]

CLA sent.