[WFCORE-26] Add launcher API

### Launcher API
The command builder will be used to build a list of parameters required to launch either a standalone or domain server.

The launcher is a simple API to ease the creation of the ```java.lang.Process```.

No dependencies are needed for the API at runtime. The library is placed in the ```bin``` directory so that it can be discovered easily. This may work for JBoss Tools, though from current conversations they ideally want something that will work with all previous versions of JBoss AS 7.x and JBoss EAP 6.x. This API does, at this point, require Java 7.

The API will however work fine the wildfly-maven-plugin and potential Gradle plugin.


### Core Test Suite
Converted the standalone test server to use the new API. The domain seems to be a bit trickier as it uses configuration files from various locations.