Improved support for sub-domains #11 and other tweaks
Fixed an issue with sitemaps on sub-domains. Sitemaps on sub-domains will not be separated into languages(since the sub-domain is already an indicator of a language).
This allows each sub-domain to have it's own sitemap that doesn't link to content in different languages.
Tried to add CORS for language sub-domains, but I'm not sure if it works :(
When running in sub-domain mode the URLs of plugin files will also be filtered(to avoid cross-domain issues).
Fixed a typo in the remove language page.