Fixes https://github.com/sbt/sbt/issues/3570
The primary motivation for bringing in Gigahorse was to speed up the dependency resolution, especially in a high-latency environment like Australia, by enabling keep-alive. One of unintended consequences was that it ended up exposing either a bug in okhttp or Nexus / Artifactory's handling of keep-alive, since corporate users behind these proxy repositories started to experience problem publishing. Multiple people have also reported that putting network proxies like HAProxy works around this issue, which seems consistent with the theory.
Now that dependency resolution has switched to using Coursier by default, I am just going to flip the default here so publishing would use Ivy's default URL handler based on `java.net.HttpURLConnection` - 5681e1a77a/src/java/org/apache/ivy/util/url/BasicURLHandler.java
Fixes https://github.com/sbt/sbt/issues/4975
This makes `CrossVersion.Disabled` a stable identifier by reverting `final def` back to `final val`.
This is to fix Scala.JS build
```
[error] ScalaJSCrossVersion.scala:34:23: stable identifier required, but sbt.`package`.CrossVersion.Disabled found.
[error] case CrossVersion.Disabled =>
[error] ^
[error] one error found
[error] (Compile / compileIncremental) Compilation failed
```
### notes
- #121 added `final val Disabled = sbt.librarymanagement.Disabled` but it was just a companion object
- #280 actually made it `final val Disabled = sbt.librarymanagement.Disabled()`, but this broke Cat's build that was calling `CrossVersion.Disabled()`
- #290 changed to `final def Disabled = sbt.librarymanagement.Disabled` and `object Disabled extends sbt.librarymanagement.Disabled`
- This changes back to `final val Disabled = sbt.librarymanagement.Disabled` (but because we changed the companion object in #290 that's ok)
Fixes https://github.com/sbt/sbt/issues/4946
1. This rewords "evicted completely" to "evicted for all versions"
2. Skips transitive and complete evictions (eviction that has no winner version)