Fix spf13/hugo#467. RSSLink now point to index.xml
Make First accept any int

TOML and YAML handles integers differently, creating issues when using integer values from configuration or front matter in the First template function.

This currently works in YAML (parses into int), but not in TOML (parses into int64).

This commit modifies First so it accepts any int.

Fixes #551
Copy content from archetype

Prior to this commit only metadata were copied from archetype on content creation.

This commit includes the content if set in archetype. This is useful in situations with similar page structure.

Fixes #556
Set Content-Type for livereload.js

The Content-Type was not set for livereload.js and was interpreteted by the browser as text/plain.

This commit sets it to application/javascript.

Fixes #562