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

tbb_filename_infos is now called outside of test_tbb. This should allow
us to test other types of things.

Move browser bundle specific stuff to pre_test and post_test sub. This
should make it possible to replace them, and reuse test_tbb sub for
testing of other things.

Return the first argument unless it is a CODE reference, in which case
we return the result from this subroutine called with the remaining
arguments.

Rather than calling yum each time, check first using rpm if the package
is already installed.

Kill it with SIGTERM, so that it can also stop its child processes.
And use waitpid to correctly end the process.

Setting LD_LIBRARY_PATH globally could cause problems with other
programs we use.