Remove glog package dependency to avoid 'flag redefined'

[tinti]

The package http://github.com/golang/glog defines several flags in its init().

When a program defines some flags and imports http://github.com/google/goexpect it may have some flags redefined.

Would be great if goexpect (due to glog) does not restrict the set of flags that can be used. For this I have two proposals:

• Drop glog completely and use log package.
• Drop glog partially by allowing the user to set their custom logger for the package. Implement glog and log interface in this custom logger.

The first one is poorly implemented here: http://github.com/tinti/goexpect

[skalle]

Thx. for explanation why you'd like to have the logger removed. I'm not very invested in glog , it's just there b/c this happens to be a google project origninally and then the standard logger used is glog.

Think the way to go here is just to swap glog for the standard logger leaving the Logging option in there for the ability to swap back to glog .

[skalle]

And btw. feel free to drop me a PR if you already have the code.

[skalle]

Thx for the PR tinti@! ..