Add multiple process option to c++ filetest template

[vexorian]

Using Template options (#96), if the filetest template has the option RunMultipleProcesses set to true, then the c++ filetest template will run each test case in a different process. This way globals will always be in the original state. Runtime errors can also be caught.

Drawbacks:

• Must reread all the sample file for each test case.
• Not sure if it works in Microsoft's c++ compiler (does system() work there?)
• Can we really expect the program to have permissions to run a different process?

Comments:

• Should this behavior be the default?
• Config file uses lowercase (Maybe camel) fields. Template starts with Upper case. Which is preferable to use for template option names?

You know, this was started after issue #90 .

[zen0wu]

Let's first discuss the awesome idea of template options. I'll have this on hold for a while.

[vexorian]

I think breaking all the variable names is more issue than it is worth.

I prefer using camels in this feature. Template variables are already not very consistent, many times foreach uses lower case.