Simple fix to unicode

Caolan,

Simple request: in two places in the default.js reporter, the actual character is used in the code, for the checkmark (passed) and the xmark (failed) for an individual test.

To make it more cross-platform and unicode (and IDE) friendly, can it be replaced by the actual unicode?

line 81: replace the checkmark with '\u2714' (that is backslash character followed by u2714)
line 84: replace the xmark with '\u2716' (that is backslash character followed by u2716)

Open the default.js reporter and inspect lines 81 and 84, where the checkmark and xmark characters are used. Replace those source characters with the specified Unicode escape sequences, then verify that the reporter still displays the passed and failed test markers correctly.

Written by the indexing model from the issue text.