Clean up OSInfo

This change removes large swaths of redundant code from the OSInfo class and
adds documentation.

Testing done:

Compiled and ran VDD.
Add class documentation to OSInfo
Rename OSInfo to Process

The class OSInfo only contains functionality to kill processes.  Change its
name here to reflect that it deals with processes.
Rename OSInfo to Process

The class OSInfo only contains functionality to kill processes.  Change its
name here to reflect that it deals with processes.
Revamp execute event

This change centralizes process handling into the Process class by giving
the execute event an overhaul.

Testing done:

Ran a script with an execute event.
Catch an exception when killing processes.

This change catches the IllegalThreadStateException that is thrown when
Process.exitValue() is called for a process that isn't dead yet.

Testing done:

VDD regression suite.
Update Selenium libs to 2.37

Testing done:

VDD regression suite.
VDD latency test suite

This is the initial commit of the VDD latency test suite.  The only currently
fleshed out test simulates a page load over a low-bandwidth connection.  More
are forthcoming.

Testing done:

slowload.xml
Add dynamic element with delayed load test

This change adds a test that dynamically loads an element some time after
the page has been loaded.  The delay before loading is configurable.

This simulates DHTML performance in a potentially high-latency environment.

Testing done:

Ran dyndelay.xml
Update Selenium libs to 2.39.0

Testing done:

VooDooTest