Merge pull request #120 from splintermind/gold

Tidyup: removes obsolete siren reactions.
maint-bin: Add our changelog automatically to SWP top-posts
Diseases are now off by default.
dev tools, tweaks and fix for #123

- updated the GUI so it's more intelligent and figures out if it needs
to modify the graphics pack files without an arbitrary setting. since we
can't trust the human, no we certainly cannot.

- added a new development tab to the ribbon (only available when the
debugger is attached) to run tests and export the settings)