git: build with RUNTIME_PREFIX enabled; http://git.661346.n2.nabble.com/PATCH-Extend-runtime-prefix-computation-td7572082.html patched applied to find the absolute argv0 path; few more files in libexec, share and lib are relocated
Merge pull request #503 from smuzaffar/IB/CMSSW_7_1_X/stable

git: fix to use runtime prefix instead of buildtime prefix