Add support for union types to callbacks

This addresses https://github.com/darobin/respec/issues/182
Use right padding for union types in dictionaries

This addresses https://github.com/darobin/respec/issues/182
Ensure that URL fragment identifiers work as intended

Currently, in most cases, URL fragment identifiers don't work as intended as the target doesn't exist yet. This module re-sets window.location.hash to jump to the right position in the document. It does this only if the document hasn't been scrolled down yet to ensure that page refreshes maintain the scroll position.
Merge pull request #193 from fhirsch/develop

Fix xmlsec bilbio.js entries, add .gitignore, add test file
Merge pull request #191 from lanthaler/fix-dictionary-union-types-padding

Use right padding for union types in dictionaries
Merge pull request #190 from lanthaler/feature-callback-union-types

Add support for union types to callbacks
Merge pull request #184 from lanthaler/location-hash

Ensure that URL fragment identifiers work as intended
take the biblio changes from Frederick
add ARIA on issues/notes; improved contrast as per WCAG; add strong to errata
v3.1.51
Merge branch 'release/v3.1.51' into develop
Merge branch 'develop' of github.com:fhirsch/respec into develop
need to bring in sync with remote