Update PRoot ecosystem graph.
Fix use of uninitialised bytes, detected by Valgrind.
Use load addresses that don't conflict with "implicit" mappings (ie. vdso, stack).

This issue was detected on Fedora 20 x86 with SE + ASLR enabled.  To
solve it definitively, the loading mechanism in PRoot should let the
kernel map position-independant segments; this will be the main topic
for PRoot v5.1.

Thanks to Rémi Duraffort for his LAVA instance.