fromWei = function(number, unit) {
    var returnValue = toBigNumber(number).dividedBy(getValueOfUnit(unit));

    return isBigNumber(number) ? returnValue : returnValue.toString(10);
}
Takes a number of wei and converts it to any other ether unit.

Possible units are:
  SI Short   SI Full        Effigy       Other
- kwei       femtoether     babbage
- mwei       picoether      lovelace
- gwei       nanoether      shannon      nano
- --         microether     szabo        micro
- --         milliether     finney       milli
- ether      --             --
- kether                    --           grand
- mether
- gether
- tether

@method fromWei
@param {Number|String} number can be a number, number string or a HEX of a decimal
@param {String} unit the unit to convert to, default ether
@return {String|Object} When given a BigNumber object it returns one as well, otherwise a number