Config: Search in Home directory

Cc: https://github.com/madskristensen/WebEssentials2013/issues/699

In JsHint and JSCS (with a [recent commit](https://github.com/mdevils/node-jscs/commit/1248aa1db499b3845b8e46414df4f8b8255b17e0)), they search for configuration file (`.jshintrc` and `.jscsrc`; JSON file with comments) in HOME directory as a fall back; if none found in the current folder ancestry (till the drives root). 

This PR enables the same for `tslint.json`.

**Points to ponder:**
- They also allow embedding configuration in `package.json`, where package.json has precedence over other formats.
- Please consider making your *default* configuration file name consistent with other linters, i.e. `.tslintrc` (now that VS introduced native support for JSON and `jshintrc` and `jscsrc`'s content type inherits JSON via Web Essentials).