Remove the Unicode BOM, if present. (#97)

[lardieri]

CSV files saved by Excel and Airtable include the BOM when encoding to UTF-8.

[DivineDominion]

LGTM, but I personally would prefer a change to the "bom" constant to make its meaning more obvious. What do you think?

Unrelated to that, would you want to merge your 0.6.2 fixes with this repo, too, so we can release that to CocoaPods proper?

[lardieri]

I've added additional documentation around the BOM.

I'm happy to submit 0.6.2 for release, but you will need to create a branch in your repo for me to open PR against, since it forks from a previous point (039cc27).

[DivineDominion]

LGTM 👍 Thanks for the doc comment!

[DivineDominion]

I've opened the branch v0.7. On top of the v0.6.1 release, it includes delimiter guessing, which was compatible with the v0.6 code. Will that be causing any trouble? Happy to discuss in another PR! :)

[DivineDominion]

Also, thanks a lot for contributing to SwiftCSV! We've invited you to join the SwiftCSV GitHub organization – no pressure to accept! If you'd like more information on what that means, check out our contributor guidelines.