* Fixes needed to build htop
* Build libncursesw.so, not libncurses.so
* Remove htop hack now that it is picking up newer ncurses
* Tell packages to link to new ncursesw libraries
Package repositories now look like this:
top-level-dir/
repo.yaml
packages/
libelf/
package.py
mpich/
package.py
...
This leaves room at the top level for additional metadata, source,
per-repo configs, indexes, etc., and it makes it easy to see that
something is a spack repo (just look for repo.yaml and packages).
