Conflict checking ignores "version" property

[HebaruSan]

Background

CKAN Version:
1.24.0

KSP Version:
1.3.1

Operating System:
Ubuntu 17.10

Have you made any manual changes to your GameData folder (i.e., not via CKAN)?
No

Problem

I set a mod to conflict with specific versions of a mod that it depends on, for testing, in this case StockalikeSolarSystem:

"conflicts": [
    { "name": "Kopernicus", "version": "2:release-1.3.1-4" },
    { "name": "Kopernicus", "version": "2:release-1.3.1-5" },
    { "name": "Kopernicus", "version": "2:release-1.3.1-6" },
    { "name": "Kopernicus", "version": "2:release-1.3.1-7" }
],

What steps did you take in CKAN?
Tried to install that mod

What did you expect to happen?
Should find a non-conflicting version of the mod, in this case Kopernicus 2:release-1.3.1-3

What happened instead?
The conflict blocks installation of the dependency completely:

$ ckan install StockalikeSolarSystem --ksp steam
The following inconsistencies were found:
StockalikeSolarSystem conflicts with Kopernicus.
Install canceled. Your files have been returned to their initial state.

Conflict checking ignores versions!

CKAN/Core/Relationships/SanityChecker.cs

Line 52 in 86bf144

// TODO: This doesn't examine versions. We should!

It looks like a lot of these more advanced but still straightforward applications of the metadata are not handled, and we're getting more instances where folk like @Sigma88 want to use them.

Found during investigation of possible workarounds for #2324.