adding modjk modules
Provide a `saltversioninfo` grain.

This helps in version comparison on templates, for example:

```python
(0, 17) > (0, 16, 3)
```
Able to connect to ESXi.

Preliminary support for libvirtd to connect to ESXi.

Tested to work with:

 virt.list_vms
 virt.vm_info <vm>

It will fall back to the default qemu connection, unless configured with:

```yaml
virt:
  hypervisor: esxi
  hostname: 192.168.9.9
```
Merge pull request #6664 from ranl/modjk

adding modjk modules
Merge pull request #6672 from holmboe/esxi

Connect to ESXi
Merge pull request #6669 from s0undt3ch/features/salt-version-info-grain

Provide a `saltversioninfo` grain.
Add rst pages for new modjk state/module

This commit tells sphinx to build doc pages for these new files, and
adds them to the table of contents.
Cleanup docstrings in modjk state/module

Fixed spelling/grammar errors, improved formatting, and introduced links
to improve doc navigation.
Typo, white-space, PEP8 and formatting fixes.
Merge pull request #6674 from terminalmage/docs

Add docs for new modjk state/module
Merge branch 'develop' of github.com:saltstack/salt into hotfix/modjk-formatting
Renamed the `lb` argument to `lbn` which is accepted by the style guide enforced by pylint.
Fix sphinx build error

When reworking the docstring for the modjk module I introduced a build
error that prevents sphinx from completing the doc build. This commit
resolves that error.
Merge pull request #6675 from terminalmage/docs

Fix sphinx build error
Add versionadded for new grains functions

This fixes #6670 by clearing up the fact that these newly-added
functions will be available in version 0.17.0.
Merge pull request #6676 from terminalmage/docs

Add versionadded for new grains functions
Merge pull request #6673 from s0undt3ch/hotfix/modjk-formatting

Typo, white-space, PEP8 and formatting fixes.
Add `versionadded` to the new `saltversioninfo` grain.