Use appveyor to build/release Windows binaries

[squeek502]

Only does the deploy phase for tagged commits

Contributes towards #200

---

Tested and confirmed to work. Example:

• Release: https://github.com/squeek502/luvi/releases/tag/v2.9.2-test2
  (the bug that caused regular32 not to get included in the release is fixed in this PR)
• Job: https://ci.appveyor.com/project/squeek502/luvi/builds/23387487
• Version Output: luvi.exe v2.9.2-test2 (i.e. it uses the tag for the version properly)

Note that the auth_token used in this PR is one I generated, and I think it'll work for the luvit/luvi repo, but maybe it makes more sense for someone else to generate it? See https://www.appveyor.com/docs/deployment/github/#provider-settings for more info about auth_token

[squeek502]

Can *.lib be ignored, what problems do they solve?

I'm not exactly sure. I included them because they were included in previous Luvi releases: https://github.com/luvit/luvi/releases/tag/v2.7.6

[zhaozg]

good job. I vote to remove *.lib for file numbers and size,if need we can add it lately

[squeek502]

Looks like the .lib files are used for linking Windows Lua modules that work with Luvi:

• [Help] wonder how luv_renamed.c implement #97
• https://github.com/virgo-agent-toolkit/lua-sigar/blob/master/CMakeLists.txt

@rphillips would probably know more.

[zhaozg]

ok #97 (comment) say clearly.