ariya/phantomjs — comment on commit 26f7185bf618080c915c750eb68a9f71190b5a72
File: src/config.cpp line 222
By detro:

AAAAAAHHHHH! Now I get it!
The webpage is cleverly used as a JSON interpreter to process the content of the given option file and apply it to the Config object itself.
It's a bit "convoluted" but, again, really clever.

Sorry, my bad.
Should sleep at night instead of reading code. :P