reading parts of a large data file

Turns out it's today. Builds from http://www.espruino.com/binaries/travis/master now have it in.

There are now 'Flash Strings' - they're special strings created only by Storage.read but basically they point to external flash and allow you to use data directly out of flash memory without loading it into RAM.

That means you can use drawImage with files stored directly in flash, but it also means that any application loaded from flash storage will have all its function code stored in and executed from external flash - which should help no end.