Valid module filenames properly.
Rename "import" to "require."
Add a bunch of standard functions to the sandbox.
Add dkjson.lua.

Modification and redistribution of dkjson.lua is permitted by its license.
Add support for command line options.
Separate Lua build flags.

This lets us pass custom Lua build flags from OpenWRT package makefiles.
Move transports into luasrc.
Set default options at compile time
Add a few new command line options.
Allow different transports for download and upload.
Add const for transport_init.
Expose censorscope options to environment scripts.
Let users set the results directory.
Expose results and sandbox dirs to transports.
Add transport for using bismark-data-transmit.
Add default options to Makefile
Fix bismark uploads path
Add bismark download sync
Remove experiments/

Fixes #38.
Fix memory leak in dns module.

See #35.