[idea] sort the import lines alphabetically

[jabbalaci]

In Python, it's common to sort the import lines alphabetically. Also, imports from the stdlib are separated with a blank line from our own imports. Could we borrow these ideas from Python?

Example:

import euler;
import std.stdio;
import std.string;
import std.conv;
import std.algorithm;
import std.array;

dfmt doesn't do anything with these lines. I think it'd look better the following way:

import std.algorithm;
import std.array;
import std.conv;
import std.stdio;
import std.string;

import euler;

Here, euler is my own module. It's separated from the stdlib modules with a blank line.