Early review of std.logger

[ilya-stromberg]

On Monday, 14 October 2013 at 11:39:52 UTC, Dicebot wrote:
> As `std.logger` is still marked as "work in progress" this 
> thread is less formal that typical pre-voting review. Goal is 
> to provide as much input about desirable `std.logger` 
> functionality and current state and let module author to use 
> this information for preparing proposal for actual review / 
> voting.
>

Add e-mail logger (useful for critical errors) for example via 
`std.net.curl.SMTP`.