gsl19test does not work properly when /bin/sh is /bin/dash

gsl19test does not work properly when /bin/sh is /bin/dash

There were 2 issues:

1) The output redirect operators seem to be bash specific. All output
   went to the terminal.....

2) When invoking valgrind the 'eval' needs to precede
  GSL_TEST_VERBOSE=1. Otherwise that environment variable is not seen
  by valgrind.

Two tweaks:

1) Determine the number of available processors and use that in make
   -j when building gsl-1.9

2) Replace -v with -q in the valgrind invocation. The file out-V is
   already quite large (approx 600 MB). It would be enormous with -v.

https://bugs.kde.org/show_bug.cgi?id=494960