Update DHT22.js

Reduce incidence of bitshifted output, slightly reduce memory in read() by eliminating a timeout.
Update DHT22.js

Fix issue with failure counter not being reset.
Update DHT11.js

Reduce memory usage slightly by removing a timeout, fix issue where readfail counter was not reset after it gives up trying to get a reading.
Update BMP085.js

Missing var declaration - was resulting in global X3 being defined.
Overhaul BMP085.js

Good lord! The minifier wasn't optimizing out the constants - so all those lovely verbose register names were being sent to the Espruino and *stored in memory*... 

Also removed comment inside function and a few very strange things that I suspect were optimized out by the arduino compiler for the module that this was adapted from. Stuff like Math.pow() on two constants...

Now the unminified version takes up 369 memory units, vs 413 for the *minified* old version.
Update AT24.js

add reads() function, to read 64 bytes at a time. Returns as a string.
Update AT24.md

document reads()
Update AT24.js

Fix wrong name for module in comment
Merge pull request #64 from SpenceKonde/master

Improve DHT22, DHT11 modules