Eigen3 install the header to QNX_TARGET

[sohamm17]

In absence of staging location, this PR installs Eigen3 to QNX_TARGET location

[dchordia]

Thanks for bringing this up. A simple fix would be to remove the CMAKE_INSTALL_INCLUDEDIR variable in common.mk and it would install to right QNX_TARGET/staging location.

[dchordia]

Adding @eleir9268 since he made last changes to build files.

[eleir9268]

We need to clean up these paths in a lot of our ports. AFAIK CMAKE_INSTALL_PREFIX and CMAKE_INSTALL_STAGING are supposed to be the only absolute paths, and CMAKE_INSTALL_*DIR are relative to those prefixes. This can fix issues with relocation.

I'm guessing you took out the CMAKE_STAGING_PREFIX and encountered errors because it tried to install data under /usr/local/share.

[eleir9268]

I would put in a change in common.mk similar to the PR #132 , the README.md change can stay the same.

[sohamm17]

I would put in a change in common.mk similar to the PR #132 , the README.md change can stay the same.

Makes sense. Done.

[eleir9268]

If you install to a staging directory without CMAKE_STAGING_PREFIX does the build succeed?