Windows Docker daemon does not support SIGINT, SIGTERM is the semantic
equivalent that allows for graceful shutdown before being followed up by
a SIGKILL.

* drivers: add config parsing tests

Add basic tests for parsing and encoding task config.

* drivers/docker: fix some config declarations

* refactor and document config parse helpers

Restore 0.8.x behavior where java driver is marked as detected when
`java -version` exits with 0 but returns unexpected output.

Furthermore, we restore behavior when `java -version` where we parse the
first three lines of `java -version` but ignore rest.

If `java -version` returns less than 3 lines, Nomad 0.8.7 would panic.
In this implementation, we'd still mark java as detected but returns
empty version.

The 0.8.7 logic for detecting java version is found in
https://github.com/hashicorp/nomad/blob/v0.8.7/client/driver/java.go#L132-L172
.

I punt on revamping how we can be more resilient to java -version
syntax, and aimed for preserving existing behavior instead.

docs: fixed some affinity examples

Docker: Fix logging config parsing

Fixes #5308

Fix executable check on windows

Issue #4649: Remove the systemd process and threads limit

systemd limits the number of process and threads you can create within the cgroup it creates for a given service. This is especially limiting if you have a high number of keys Nomad watches from Consul.

Fixes #4649

Fixes
https://groups.google.com/d/topic/nomad-tool/B3Uo6Kns2BI/discussion

The test used old local copies of Docker structs and appeared to be
testing an outdated approach to task config decoding.

Updated to use real Docker structs so we can do end-to-end unit testing
of real Docker task configs.

No need to pass in the entire eval context

Only log when syncing actually did something.

Will hopefully help us catch deadlocks/livelocks/slowdowns in the
add/remove allocs pipeline which should be fast.

nomad/command: fix strings.Contains args order

Swapped call args order to meet the expected behavior.
Signed-off-by: Iskander Sharipov <quasilyte@gmail.com>

UI: Always show an absolute timestamp tooltip when showing relative dates

cli: do not duplicate reschedule headers per group

Fixes #5291

Fix typo in "discovery"

fix typo

Bump to Nomad 0.8.7 and mention 0.9 beta

Change types of weights on spread/affinity

website/resources: add recent videos/blogs to resources