Adapt to HEMTT

[jonpas]

When merged this pull request will:

• Use HEMTT as build system (uses armake2)
• Add build.bat for quick Windows builds without command line and build_release.bat for release builds
• Add script setup.bat to download project-specific HEMTT binary
  • No Linux script as downloading an artifact requires authentication
• Swap Travis CI and Circle CI with GitHub Actions
  • No builds yet as Actions HEMTT is too old version (/ comment bug)
• Add custom HEMTT versioning script
  • Update versions in files (like make.py) in prebuild and reset in postbuild
  • Version source is addons/main/script_version.hpp
• Documentation

TODO armake2/HEMTT:

• Fix subconfig not processed correctly (Subconfig not processed correctly KoffeinFlummi/armake2#45)
• Fix preprocessor define and comment on same line (Define and comment on same line KoffeinFlummi/armake2#24)
  • Remove temporary removal of comments
• Fix preprocessor comment with / on same line (example) (BrettMayson/HEMTT@477e44c)
• Folder copy on release (Files in sub-folder copy options BrettMayson/HEMTT#88)

---

TODO CBA Later (User):

• Use HEMTT file-patching symlink setup instead of setup.py
• Add release/publish procedure (ref. Changes for armake #730 (comment)) (HEMTT script)
• Use Windows Installer instead of project-specific binary and download script (Windows Installer BrettMayson/HEMTT#60) Will stay project-specific
• Revert Nobin XEH (Mikero tools workaround) #1199

TODO HEMTT Later:

• Release HEMTT 0.7.5 and use in CI (contains / comment and folder copy on release) (Tools - Show version when installing HEMTT #1317)

[jonpas]

Release/publish procedure idea (in combination with BrettMayson/HEMTT#16 (comment))

$ hemtt version -i minor
$ hemtt build --release -f
$ hemtt run publish

Configuration to achieve above:

version = "3.12.0.{{date \"%y%m%d\"}}" # eg. "3.12.0.190515"

[scripts.publish]
show_output = true
steps = [
    "@version -i build", # Would automatically use date specifier as above
    "git commit -am \"Bump to v{{version}}\"",
 	"git push"
]

---

Ideally, we could also do the following, but HEMTT needs to support running its own commands from user-defined scripts.

$ hemtt version -i minor
$ hemtt run release # Update versions, commits them, build release (maybe better name?)

[scripts.release]
show_output = true
steps = [
    "@version -i build", # Would automatically use date specifier as above
    "git commit -am \"Bump to v{{version}}\"",
    "build --release -f", # After version commit, we want headerext to be up-to-date
 	"git push" # Push prep/bump commit
]

[commy2]

Why does it delete comments at the end of the line? They are actually helpful.

[jonpas]

Why does it delete comments at the end of the line? They are actually helpful.

Again, read the commit title. It is temporary so I can test the rest until it gets fixed in armake2. It's even on TODO above...