GCS/Config: allow board plugin to specify custom config page

Previously a custom page for CC3D was hardcoded into the general
code, which obviously does not abstract well. This moves that
functionality to the board plugin, and when not provided uses
the same default configuration.
GCS CopterControl: move custom dialog to board plugin
GCS: update copyrights
Merge pull request #1257 from peabody124/board_config

Board configuration in the plugins