Add a scheduler service to the framework

# **Quartz.NET Scheduler:**
I have implemented the Quartz.NET Enterprise Scheduler to the framework.
http://www.quartz-scheduler.net/

I've added two types to the project. 
* Scheduler
* Job

The Scheduler holds Jobs. On each Job, multiple Tasks can be registered using an xtype descriptor. The descriptor asks for a Task name and the fully qualified class name of the Task.

I've added an abstract Task class that needs to be inherited from. This class implements the Quartz IJob interface. The only thing that is needed to create a Task is to implement the member DoExecute().

For now, I have only implemented a simple scheduler trigger, that takes these three arguments:
* seconds
* minutes
* hours

These settings can be configured on the xform. The next run will be scheduled depending on the last run.

Because multiple Tasks can be configured per Job, the xform will show the status of each Task separately. It will show if the Task ran successfully, if it gave any exceptions and the Task output (if present).

# **Example:**
I've added an example type called **ExampleJob** to the TestWebApp project.
This Job has multiple Tasks. One of the tasks will always fail (**FailingTask**), to demonstrate the exception handling. Another one (**ExampleTask**) will divide random numbers, and could fail or run successfully, depending on the randomly selected divider, that could be zero.

# **Screenshot:**
![job](https://cloud.githubusercontent.com/assets/1898162/4781345/5cf0d47a-5c99-11e4-9487-4732715a9f1e.JPG)