Add: format add `%t` placeholder
Add: add stackIndex opt to specify the index of stack for getting file information.
Merge pull request #18 from Bacra/bacra-push

Set showHidden and depth opts are independent for each tracer Instance
no message
Merge branch 'master' of https://github.com/baryon/tracer

Conflicts:
	.travis.yml
v0.7.0
Fix: `format` stringify json error

Json have hidden cycle call. Add try catch as well as `util.format` in nodejs
v7.1 merged from Bacra
Merge branch 'master' into bacra-master
Merge branch 'bacra-dev' into bacra-master

Conflicts:
	lib/console.js