allow custom barChar character, or non utf8 option

[mattkime]

not all logging environments support utf8 which can result in - � instead of ▇

it would be nice to replace it with the line character in 'figure', assuming its a ASCII char.

unfortunately its not clear how i might pass config option to grunt-time. might be obvious after a little digging.

this would also address this issue - #52

[sindresorhus]

not all logging environments support utf8

What kind of logging environment doesn't support UTF-8 in 2015?

[kevva]

Probably something Windows.

[mattkime]

nope, linux. digging up more info from coworkers about why this is the case.

[tomasstankovic]

I think we can close this. But if someone has a problem currently, please write here and we will try to resolve it.