small bug in getApiSignature (with fix)

[etx]

Hey!

Thanks for the very useful code, it's great. I found a small bug.

In getApiSignature at line 832 you're using for(var index in keys). This was causing the functions in my array prototype to be added to the string that is used to build the MD5 hash. Switching it to this (below) fixed it right up. I'd commit a patch or something but I'm no good at git.

for(var i=0; i<keys.length; i++){
var key = keys[i];
string += key + params[key];
}

[fxb]

Fixed.