update to 0.9.19 release
Merge branch 'gh-pages' of github.com:bruceravel/demeter into gh-pages

Conflicts:
	aug/import/preproc.html
	aug/other/plugin.html
	aug/other/prefs.html
	aug/params/constrain.html
	aug/process/mee.html
	aug/process/pixel.html
	aug/process/sa.html
	aug/ui/mark.html
	pods/index.html