fix(tiller): don't update purged releases

feat(tiller): add {{.Capabilities}} object

fixes #1807

This adds the {{.Capabilities}} object to the template variables so that
chart authors can write charts that are aware of teh Kubernetes
capabilities of the current cluster.

Closes #1608

"spring" should be "sprig"

clarifying _ files, adding syntax highlighting

fix(tests): fix testclient reactions that were not triggering

making precedence explanation less ambiguous

ref(*): remove dead code

Add `--upgrade` option to `init`. Fixes #1782.

fix(tiller): s/POD_NAMESPACE/TILLER_NAMESPACE/

Align output of helm status resources output

Improve `helm status` help text

fix(helm): prevent .helmignore rules from applying to '.'

text/tabwriter is used to align resource list in columns

`helm status -h` now shows what kind of information is displayed when
running `helm status`

When option is given, any existing Tiller will be upgraded to the current version

RIP

Closes #1776

Add ARM target for binaries

docs: kubernetes_distros: complete note about socat on Container Linux

chore(*): bump to v2.1.3

Fix typos and spelling errors

 Installation guide link is wrong in install FAQ

This fixes two things:

1) CoreOS Linux is now Container Linux https://coreos.com/blog/tectonic-self-driving.html#coreos-linux-is-now-container-linux

2) Provide more technical details on what is going on for users trying
to debug and understand

It links to install.yaml instead of install.md: https://github.com/kubernetes/helm/blob/master/docs/install.md

ref(tiller): dry up client/server version checks

Update docs for new Homebrew formula

feat(tiller): validate objects against kube schema on dry-run

docs(install_faq): document tiller panic for auth failure