YARN + pact-client enhancements, fix stalling travis builds

* YARN now also starts the web interface
* extended pact-client to nicely support remote execution using new option "remote"


```
Action "run" compiles and submits a PACT program.
  "run" action arguments:
     -a,--arguments <programArgs>   Pact program arguments
     -c,--class <classname>         Pact program assembler class
     -j,--jarfile <jarfile>         Pact program JAR file
     -w,--wait                      Wait until program finishes

Action "remote" is similar to "run" but allows to specify the JobManager connection
  "remote" action arguments:
     -a,--arguments <programArgs>   Pact program arguments
     -c,--class <classname>         Pact program assembler class
     -j,--jarfile <jarfile>         Pact program JAR file
     -r,--address <arg>             Hostname:port of JobManager
     -w,--wait                      Wait until program finishes
```

The webinterface starts but is not really usable from the YARN webinterfaces due to https://github.com/stratosphere/stratosphere/issues/325.