Implement #149: Phantom CLI args via Capabilities

Example Usage to accept self-signed certificates:
String[] args = { "--ignore-ssl-errors=yes" };
capabilities.setCapability(PhantomJSDriverService.PHANTOMJS_CLI_ARGS_CAPABILITY, args);
Merge remote-tracking branch 'upstream/master' into 149-cli-args-capability
add code documentation and refactor for consistency
remove unnecessary javadoc

public static final values are exposed in the javadoc automatically
Merge pull request #154 from c089/149-cli-args-capability

Implement #149: Phantom CLI args via Capabilities