CMake configure error

[godbyk]

@rpavlik In the improve-linux-config-search branch there are two files: cmake/InstallDebugSymbols.cmake and cmake-local/InstallDebugSymbols.cmake. CMake is loading the former and not the latter. So the osvr_install_symbols_for_target function in the latter isn't being defined, causing a CMake configure error.

[rpavlik]

Thank you for finding this. I've updated #589 (where you pushed the one patch) to also go down to a single copy of this file, and the right copy.

[rpavlik]

And the travis build is fixed again :)