Add build_config.h to gitignore, untrack

To be generated on the host and used only when building.

Signed-off-by: James Warren <admin@trezanik.org>
Amend configure ps1 script to output in ASCII

Appears as a binary file within git otherwise. Has been untracked, but
still a change that should be done to remove a BOM.

Signed-off-by: James Warren <admin@trezanik.org>
Add json-spirit to configure scripts

Signed-off-by: James Warren <admin@trezanik.org>
Update doxygen

- Amend gitignore to keep the .exe
- Don't bother retaining the original doxygen css when using custom one
- Remove original doxygen css

Signed-off-by: James Warren <admin@trezanik.org>
Update to use official JSON Spirit code (v4.08)

Copy scripts updated to new folder/file structure
Old third-party code removal, new additions
Documentation and link amended

Signed-off-by: James Warren <admin@trezanik.org>
Partial: RPC + json spirit implementation