Update MEK for new Essentials version.

[ShellyHerself]

Update the MEK for the new MEK_Essentials that will soon be reviewed. There is a lot of files changed. But most of that is just the same changes being applied to some generic files and a bunch of deletions.

This should not be merged until these are reviewed:

• https://github.com/Sigmmma/binilla/pull/24
• https://github.com/Sigmmma/mozzarilla/pull/29
• https://github.com/Sigmmma/refinery/pull/21
• https://github.com/Sigmmma/hek_pool/pull/5

Global:

• Add meklib to gitignore while not breaking the __init_\.py
• Rename some files to be friendlier.
• Delete some old duplicate files.
• Rename install instructions to readme and remove some old not required steps.
• Update get_pip.
• Delete visual studio runtime installer.

MEK_Installer:

• Update download URL.
• Add argument parsing for when this gets invoked by the MEK_Essentials.
• Increase GUI scale a tad.
• Simplify subprocess running code.
• Subprocess output is not delayed anymore on Linux.
• The pip-check is insane now. Maybe too insane.

Runners:

• Update runners for the new main method structure that the projects will soon have.
• Foolproof the Python version checks more.

[ShellyHerself]

This is ready for review whenever the other mentioned PRs are reviewed.

[ShellyHerself]

Now! it's ready for review

[ShellyHerself]

Merged Master in and resolved conflicts.

[ShellyHerself]

I need to merge this. Too many people are having issues with the MEK