Set bot useragent for Inflator

[HebaruSan]

Background

CKAN and Netkan both use a default User-Agent of Mozilla/4.0 (compatible; CKAN).

Motivation

This User-Agent does not identify the Inflator as a bot, which it most certainly is.

See KSP-SpaceDock/SpaceDock#436 for why we might want to do that.

Changes

I don't know if there's a comprehensive reference on how to create a User-Agent string; the best reference I was able to find was:

• https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/User-Agent#crawler_and_bot_ua_strings

Based on the examples presented there, the Inflator's User-Agent is now:

Mozilla/5.0 (compatible; Netkanbot/1.0; CKAN; +https://github.com/KSP-CKAN/NetKAN-Infra)

I think parsers will just check whether bot occurs in the browser family.

Blocking external dependencies

The HyperEdit and Graphotron mods use a combination of strange URLs:

• http://www.kerbaltek.com/_IamCKAN_Gimme_hyperedit_#cachebuster1
• http://www.kerbaltek.com/_IamCKAN_Gimme_graphotron_

... and the User-Agent string to identify Netkan requests. Requesting these URLs with the wrong User-Agent string results in an HTTP status 403 error. Before we merge these changes, we must work with @Ezriilc to update the kerbaltek.com site to support the new User-Agent formats as well as the old format.

[DasSkelett]

Without having fully understood the syntax, do you think it would be possible to include the word CKAN somewhere? It would be nice to have that reference for people who don't know what Netkan is supposed to be but do know about CKAN.
Technically it's in the link, but having it separately, if possible, makes it stand out more.

[HebaruSan]

Done in this PR, going to the next now...

[DasSkelett]

HyperEdit and Graphotron are working again right now, let's see what happens when we deploy this. But it's probably easier for @Ezriilc to work with a stationary target, and with the logs showing the new user-agent string.

[Ezriilc]

HyperEdit and Graphotron are working again right now, let's see what happens when we deploy this. But it's probably easier for @Ezriilc to work with a stationary target, and with the logs showing the new user-agent string.

However, don't let me become a problem. Y'all do your thing and I'll try to keep up. lol