Plugin-Plane

* Remove boost dependency
* Make the CMakeLists.txt reusable
* Add more configuration options and remove ReForm-specific defaults
* Clean up the File interface and implementation
* Clean up definitions of helper and stream functions
* Use the configured print function for debug output to the console instead of streaming to std::cerr
* Clean up the File flags and HTML support (unused)
* Simplify File and Config to avoid deallocations on app shutdown
* Update (C) notices, clean up code
* Add the macro DEB_if() to simplify the DEB_if_*() macro implementations