fixes bug 901177 - build system changes for json stackwalker
Fixes bug 926078 - updates stackwalker

This reverts commit 2d0486fbcf317f3bb90e2828136befa3a95288e0.
fixes bug 927049 - package source and libs needed for JSON stackwalker
bug 927049 - fix up centos docs and vagrant for GCC 4.7
fixes bug 927049 - package source and libs needed for JSON stackwalker