added separate VBEM function in ash;added small test in ash.test.R
updated test of vb method; updated intro
Merge branch 'master' of https://github.com/stephens999/ash

Conflicts:
	Rcode/figure/unnamed-chunk-10.png
	Rcode/figure/unnamed-chunk-12.png
	Rcode/figure/unnamed-chunk-3.png
	Rcode/figure/unnamed-chunk-5.png
	Rcode/figure/unnamed-chunk-6.png
	Rcode/figure/unnamed-chunk-71.png
	Rcode/figure/unnamed-chunk-72.png
	Rcode/figure/unnamed-chunk-8.png
	Rcode/figure/unnamed-chunk-9.png
	Rcode/intro.html
	Rcode/intro.md