Add: Example of how to use metatags

Thanks @tzz
Merge pull request #900 from nickanderson/redmine/6228

Add: Example of how to use metatags
Fix document tags

Remove left-over stuff from copying a different files header.
Fix document ordering

Fix document ordering so that it does not duplicate another position and
so that it comes before custom inventory.
Merge pull request #901 from nickanderson/redmine/6228

Fixups for Tags tutorial
Fix: Rename with proper extension
Merge pull request #902 from nickanderson/redmine/6228

Fix: Rename with proper extension
Add cf3 syntax highlighting

It makes it easier to read.
Merge pull request #903 from nickanderson/redmine/6228

Add cf3 syntax highlighting
Add new promise types
Redesign of guest promises means a complete change of syntax
Add body for internal routing services, implicit promises
Add missing header
Document extensions to db promises, and change to column type syntax
Document expandrange
Spacing changes and edit table summary
Alter services text
Debugging doc system
Debugging doc system 2
Debugging doc system 3