deprecate old mavenPublish extension

[gabrielittner]

This deprecates the old sonatypeHost and releaseSigningEnabled properties on the DSL. It also prepares for the following release to not add maven central as a default publishing target and not to enable release signing by default anymore.

Everyone currently publishing through maven central or signing releases without explicitly configuring it will get a warning. To get rid of the warning and prepare for the new behavior

SONATYPE_HOST=DEFAULT
RELEASE_SIGNING_ENABLED=true

(SONATYPE_HOST=S01 if s01.sonatype.org is used) needs to be added to the Gradle properties. Alternatively it's possible to use the new extension:

mavenPublishing {
    publishToMavenCentral("DEFAULT")
    signAllPublications()
}

Those 2 methods are now also not incubating anymore.

I've already updated the README because the properties are already fully supported.

[vanniktech]

I really don't like that you have to specify this, why can't we do default always and only if you want to change it, you have to declare it

[gabrielittner]

In general there are 2 reasons for this

• I think it's generally safer to not add something by default, this way you won't accidentally publish something internal by just running publish
• From the plugin perspective we can avoid a lot of edge cases by having less afterEvaluate blocks, we won't be able to get rid of all of them (like when detecting which plugins are applied to the build) but at least some.

With properties we can still offer easy, low overhead configuration without the cost of afterEvaluate. If you want to publish to maven central you need to add the other properties anyways so it doesn't really increase the setup cost.

The reason for not using default as the value when no property is present is that it won't work well with the DSL. We would then call publishToMavenCentral(DEFAULT) immediately and users wouldn't be able to call publishToMavenCentral(S01) if the prefer to use the DSL over properties.

[vanniktech]

Same here as above