patch for configure to use the static GSL libraries.
When using it on a Linux 64 bit machines (like SLC4 with gcc3.4), one must have compiled GSL with the option -fPIC also for the static library.
This is done by using the GSL configure option --with-pic

With these changes the LD_LIBRARY_PATH to GSL is not needed anymore when running or building stressMathMore


git-svn-id: http://root.cern.ch/svn/root/trunk@21324 27541ba8-7e3a-0410-8455-c3a389f83636