Try to merge macmahon's branch into masa's for Ruby 2 support

Merge branch 'master' of https://github.com/david-macmahon/rb-gsl into macmahon

Conflicts:
	.gitignore
	AUTHORS
	README
	Rakefile
	VERSION
	ext/array.c
	ext/array_complex.c
	ext/blas1.c
	ext/block_source.c
	ext/dirac.c
	ext/error.c
	ext/extconf.rb
	ext/fft.c
	ext/function.c
	ext/graph.c
	ext/gsl.c
	ext/histogram.c
	ext/ieee.c
	ext/integration.c
	ext/linalg.c
	ext/linalg_complex.c
	ext/matrix_complex.c
	ext/matrix_int.c
	ext/matrix_source.c
	ext/multifit.c
	ext/multimin.c
	ext/odeiv.c
	ext/poly_source.c
	ext/sf_bessel.c
	ext/sf_coulomb.c
	ext/sf_coupling.c
	ext/sf_dilog.c
	ext/sf_elementary.c
	ext/sf_elljac.c
	ext/sf_exp.c
	ext/sf_gamma.c
	ext/sf_gegenbauer.c
	ext/sf_hyperg.c
	ext/sf_laguerre.c
	ext/sf_legendre.c
	ext/sf_log.c
	ext/sf_power.c
	ext/sf_trigonometric.c
	ext/signal.c
	ext/siman.c
	ext/stats.c
	ext/vector_complex.c
	ext/vector_double.c
	ext/vector_source.c
	ext/wavelet.c
	include/rb_gsl.h
	include/rb_gsl_array.h
	include/rb_gsl_common.h
	setup.rb
	tests/gsl_test2.rb
	tests/poly/poly.rb