Add tty detection for MSYS terminals.

[BurntSushi]

This improves the tty detection in MSYS terminal environments on Windows. Specifically, it uses heuristics to determine whether a standard handle is a pipe or a tty.

Behavior in normal Windows consoles remains unchanged.

Fixes #10

[BurntSushi]

We should try to get #11 merged first. Once that's done, I'll rebase this PR. :-)

[coveralls]

Changes Unknown when pulling 1c423c378c26ecd4973fc9513700d560b22c8e99 on BurntSushi:mintty into on softprops:master.

[coveralls]

Changes Unknown when pulling 1c423c378c26ecd4973fc9513700d560b22c8e99 on BurntSushi:mintty into on softprops:master.

[BurntSushi]

@softprops Thanks! If CI passes, then I think this one should be good to go too. :-)

FWIW, I realize this implementation is a bit gnarly. I'd be happy to play unofficial maintainer. I'm watching this repo, so I'll keep an eye on it if any bugs crop up.

[coveralls]

Coverage remained the same at 100.0% when pulling 818dda7891a07dca6254f2079ff256a85e04cd59 on BurntSushi:mintty into ca2ab17bdedd88cd2c912debd724b79cf9b1a802 on softprops:master.

[coveralls]

Coverage remained the same at 100.0% when pulling 818dda7891a07dca6254f2079ff256a85e04cd59 on BurntSushi:mintty into ca2ab17bdedd88cd2c912debd724b79cf9b1a802 on softprops:master.

[coveralls]

Coverage remained the same at 100.0% when pulling db8d55f88eabfcc22cde39533c2b1d688d1cdfc6 on BurntSushi:mintty into ca2ab17bdedd88cd2c912debd724b79cf9b1a802 on softprops:master.

[coveralls]

Coverage remained the same at 100.0% when pulling db8d55f88eabfcc22cde39533c2b1d688d1cdfc6 on BurntSushi:mintty into ca2ab17bdedd88cd2c912debd724b79cf9b1a802 on softprops:master.

[BurntSushi]

@softprops Thanks! Sorry to be a bother, but could you also publish a new release too?

[softprops]

done