updates to docs referencing debugging mode

- making a small change to the way the /inexp route is handled.  previously this route was basically ignored when running in debug mode.  however, the /exp route already ignores the meaning of the database status field when in debugging mode.  Thus, i think it makes more sense for everything to proceed as normal and to just ignore the usual safety checks re: restarting experiment mid-way rather than hacking the status codes to force this behavior.
conceptual information about experiment structure
some typos, etc...
file no longer exists, can't be preloaded
don't mark quitters in debug mode, don't block ads in debug mode
updated error page

- boostrapped
updating CSS paths to work on ad server