Release notes freestyler v6.1803.17

This was a large release containing 2 big subjects:
1) being able to manage the talking to external html proxy servers (for html cache).
2) being able to build html emailtemplates for outgoing html emails.
But also several small wishes, issues and additions are implemented.

Release summary

Added:
Resource versioning for online css/js files. In order to bypass local cached files.

Added SSL + Proxy support:
Used for serving fs3 generated html to an external webserver (i.e. Apache).

Added Emailtemplate support:
Used for sending styled emails to website customers or website moderators.

Added new backend search:
For specificly searching in the seoFriendly url

Added to mailroom:
- email template handling
- loadlayer where relevant
- tabs on config
- legenda on all overviews
- cleaning of uploaded files
- statechanges for shopping

Changed language database:
- now caching all lookups
- all code conform fs3 standards