* improved error messages on HTTP errors
* strip whitespace in all lines, including comment lines (gpotdevin)
* added new magics: %method (alexisdimi), %http_header, %load
* added new option `none` to %format magic, for manual control of format request
* can read `%auth` parameters from environment variables
* do not print out password for `%auth` magic
* magic processing split out to magics.py