doc build
Update comments; requirejs needs to be installed globally
new build
comments; use self.override and self.defineProperty where it makes sense
Add prefix, configurable, and backingVariable to properties

Properties starting with “_” will automatically use the “_” prefix; but
prefixes could be any valid JS identifier. configurable is the same as
Object.defineProperty’s configurable. backingVariable indicates if a
private backing variable should be created (not necessary for computed
properties).
fix backingValue -> backingVariable
comments
formatting