Bugfix/parsing error in csv transaction

There is a bug in the code that creates a transaction from a CSV file. Amounts which cannot be represented precisely in floating point are not correctly converted to an integer amount of satoshis. See the commit message of https://github.com/shunyata/electrum/commit/acec9c2b4313a65dca42ce106cfe442680a09201 for more information.

Note: I also removed a lot of trailing whitespace. The change which fixes the bug is in https://github.com/shunyata/electrum/commit/acec9c2b4313a65dca42ce106cfe442680a09201