Crude fix to identify Annex B deprecated functions

This is a crude quick fix to identify functions noted in ES5 Annex B as nonstandard or deprecated: notably 'escape', 'unescape', 'substr' and the non-Y2K-friendly 'getYear' and 'setYear'

This addresses an open issue in the 2.x codebase ( https://github.com/jshint/jshint/issues/1092 )

Although this is contrary to the goals for current (3.x) jshint development, I believe this should be included in 2.x jshint for the following reasons:

1. substantial interest including small ($50) bug bounty
2. Implementing this change and running it against jshint source identified ~10 uses of the nonstandard 'substr' in jshint sources, which were replaced by 'substring' (see pull request)

The option to enable this behavior is named 'legacy'; the behavior is enabled by setting legacy: true