This replaces the old set parser with a brand new one. This also changes
the internal algorithm from duplicating YAML to merging YAML, which
might solve a problem one user reported in chat, but which was never
captured in an issue.

Closes #1540
Closes #1556

Downloading of charts and helm itself happened over http. This
change moves to use https as that is available with valid certs.

A bucket name in the path can be migrated to a custom k8s domain
name. This is in preperation for that.

This refreshes docs, as discussed in #719, and adds a few new sections
to the docs.

Closes #719

This removes the requirement that a fetch or install command must
explicitly state the version number to install. Instead, this goes to
the strategy used by OS package managers: Install the latest until told
to do otherwise.

Closes #1198

Closes #1271

The old form is marked deprecated.

Relates to #1196

Fix typo in using_helm.md that refers to "glide install".  The
reference should be to "helm install".