More gfortran-compatibility tweaking.

	modified:   makefile
Added TSPACK tensioned spline interpolation library and replaced
effective area interpolation calls with TSPACK calls instead of
curv* FITPACK calls.  Also corrected an initialisation bug
in the effective area.

	new file:   contrib/TSPACK/ARCL2D.f
	new file:   contrib/TSPACK/ARCL3D.f
	new file:   contrib/TSPACK/B2TRI.f
	new file:   contrib/TSPACK/B2TRIP.f
	new file:   contrib/TSPACK/ENDSLP.f
	new file:   contrib/TSPACK/HPPVAL.f
	new file:   contrib/TSPACK/HPVAL.f
	new file:   contrib/TSPACK/HVAL.f
	new file:   contrib/TSPACK/INTRVL.f
	new file:   contrib/TSPACK/SIG0.f
	new file:   contrib/TSPACK/SIG1.f
	new file:   contrib/TSPACK/SIG2.f
	new file:   contrib/TSPACK/SIGBI.f
	new file:   contrib/TSPACK/SIGBP.f
	new file:   contrib/TSPACK/SIGS.f
	new file:   contrib/TSPACK/SMCRV.f
	new file:   contrib/TSPACK/SNHCSH.f
	new file:   contrib/TSPACK/STORE.f
	new file:   contrib/TSPACK/TSINTL.f
	new file:   contrib/TSPACK/TSPBI.f
	new file:   contrib/TSPACK/TSPBP.f
	new file:   contrib/TSPACK/TSPSI.f
	new file:   contrib/TSPACK/TSPSP.f
	new file:   contrib/TSPACK/TSPSS.f
	new file:   contrib/TSPACK/TSPT1.f
	new file:   contrib/TSPACK/TSVAL1.f
	new file:   contrib/TSPACK/TSVAL2.f
	new file:   contrib/TSPACK/TSVAL3.f
	new file:   contrib/TSPACK/YPC1.f
	new file:   contrib/TSPACK/YPC1P.f
	new file:   contrib/TSPACK/YPC2.f
	new file:   contrib/TSPACK/YPC2P.f
	new file:   contrib/TSPACK/YPCOEF.f
	new file:   contrib/TSPACK/readme.txt
	modified:   history.txt
	modified:   makefile
	modified:   src/flatCommon.f90.template
	modified:   src/flatIRFini.f90
	modified:   src/flatIRFs.f90