Update Source.cpp to use more recent Oculus SDK

[clebio]

I had a devil of a time trying to compile the source, until I realized that it's built against the v0.2.x SDK. Once I switch to the older ovr_sdk_win_0.2.5c.zip SDK files, I was able to get the project to compile pretty easily.

The breaking changes are detailed in the v0.4 SDK Developer Guide (pdf) in Appendix A.1 Changes since release 0.2.

I realize you probably don't have the bandwidth to make the updates (and presumably later SDKs may break backwards compatibility as well), but I'm logging the issue in case others struggle with this as well. Would be simple enough to add a note to the readme that the project is meant to be built against the v0.2 SDK.