v0.3.11 Moved biom-demo.Rmd to vignettes/. Updated inst/NEWS file to official format.

Removed pre-built vignette HTML so that it is re-built during package
build. This updates things like the build-date in the vignette, but
also ensures that the user sees in the vignette the results of code
that just worked with their copy of the package.
-built version passes all tests. No warnings.