New panagenda DataMiner Features

• Use HTTP Header variables in queries
  Queries, called via the DataMiner WEB API, can now include HTTP Header variables send by the calling web client. All header variables are rendered into the system, named:
  `HTTP_HEADER_<headername in camelcase>.`
• New, aditional template language
  Queries now support, in addition to the current template language (:<name>), a new template language.
  The new template system is based on the lodash template functions. How to use these templates and variables can be found here:
  https://lodash.com/docs/4.17.5#template

Bug Fixes

• An error, where the query id was lost when opening an DM internal link while being unautheticated, was fixed.
• An error, where it was impossible to call an query with the external web API, was fixed.