AngelScript update

[wipe2238]

Yeah, this one is unavoidable, neither engine or any server can live on their own without AngelScript.
Before we can even think about reporting or requesting... well, anything, we have to start using something what isn't five years old. Andy is a great dev but even him won't support version as ancient as what we have here.

Best idea as of now is to make series of dedicated updates for AngelScript only, going step by step.
Update to 2.26.1 and release. Update to 2.26.2 and release. Update to 2.26.3 and... yup, you guessed this one - release. It makes an absolutely boring changelog, but gives servers time to apply fixes without worrying about noise coming from engine. Plus, as i'd go with that a harsh way, and start treating all warnings coming from compiler as errors (at least until we reach latest stable), they'll need extra focus anyway.

Currently engine uses v2.26.0
Full list of changes can be found here.

2013

• 2.26.1
• 2.26.2
• 2.26.3
• 2.27.0
• 2.27.1

2014

• 2.28.0
• 2.28.1
• 2.28.2
• 2.29.0
• 2.29.1
• 2.29.2

2015

• 2.30.0
• 2.30.1
• 2.30.2

2016

• 2.31.0
• 2.31.1
• 2.31.2

2017

• 2.32.0

[wipe2238]

With open-source and CI artifacts, idea of dedicated releases changed to dedicated tags: each AS update with own tag (vN-angelscript-2.XX or vN-angelscript-2.XX.Y) and a single release with most-recent version.
Release should contain links to appveyor artifacts, which give anyone 6 months to grab ready-to-use release packages, later they're on their own.

Less manual work with same results and, as a bonus, @BartAdv might regain faith in my sanity.