Some xpcshell tests fail if there is no X server available.

Make readelf_RELRO, readelf_stack_canary, readelf_no_rpath tests produce
warnings rather than errors on failure.

All current TBB versions now use the same fteproxy path.

Get the number of cpu by looking at /proc/cpuinfo

Public domain image downloaded from:
http://www.wpclipart.com/computer/icons/other_icons/exclamation_triangle_blue.png.html

And use it in report.html