Keep multiline array literals at same indent.

[rcorre]

This doesn't fix all issues with multiline arrays, but at least fixes this simple case:

If the current line and the line above both begin with an array literal, align
the current line with the above line.
Resolves #26.

Keeps multiline 2D array definitions aligned like so:
auto a = [
[1, 2, 3],
[1, 2, 3],
[1, 2, 3],
];

Previously they were aligned like so:
auto a = [
[1, 2, 3],
[1, 2, 3],
[1, 2, 3],
];

[whitebyte]

Thanks, it works. BTW what are other issues with arrays?

[rcorre]

If you put the opening brace on a newline, you get:

auto a = 
[
[ 1, 2, 3 ],
[ 4, 5, 6 ],
[ 7, 8, 9 ]
];

I haven't actually found a ftplugin that gets it right though. For example, Ruby gives:

arr = 
  [
    [ 1, 2, 3 ],
    [ 4, 5, 6 ],
    [ 5, 6, 7 ]
]