defaultsTo as a function not allowed anymore in v1

**Sails version**: 1.0.2
**Node version**: 8.4.0
**NPM version**: 5.7.1
**DB adapter name**: N/A
**DB adapter version**: N/A
**Operating system**: CentOS 7

**Expected behaviour**
In sails.js 0.12, a function could be used for the defaultsTo attribute, for example, if you want to default to a string of the current date with the moment.js library (defaultsTo: () => moment().toISOString()).

**Actual behaviour**
This no longer works. It errors indicating an inconsistency with the specified input type and the defaultsTo type. Using moment() or new Date() as a non-function does not work; it defaults to the date in which the action/modal was loaded, rather than the date the action/modal was called. A function is necessary to default to the current date. But it will not allow that.

Start by reproducing the reported defaultsTo behavior in Sails 1.0.2 with a function returning the current date, then compare it with the Sails 0.12 behavior described in the issue. Done means function-valued defaultsTo is accepted and evaluated when the action or model is called rather than when it is loaded.

Written by the indexing model from the issue text.