Renovate now ignores any upgrades that are marked as deprecated, unless the current version is itself also deprecated. The new config option `ignoreDeprecated` can be set to false to disable this if necessary.

Closes #1988

Raises a deprecation warning issue per-dependency. Uses logic that if latest version is deprecated then the package is deprecated.

Closes #1592

Adds logic to detect presence of “deprecated” field in latest version. First step towards #1592

This reverts commit b46a95a9.

This reverts commit 04e0ca1f.

Refactors credentials/token handling to rely less on env variables and instead use an endpoints middleware for credentials handling.

First step towards #2105

Renames "date" and "time" values from datasources to instead be "releaseTimestamp".

Adds a wrapper to all datasources to provide a generic purl-based interface.

Closes #1764 

This PR follows up and fixes #1968

The previous PR didn't behave correctly as it was expecting Github Enterprise to ALWAYS been configured and that the github.com token was available in the `GITHUB_COM_TOKEN` env variable.
But for non GHE project `GITHUB_COM_TOKEN` is not defined and github.com token is available at the `GITHUB_TOKEN` env variable instead.

This updated PR fix this issue and avoid further problems by prioritising `github.com` over GHE.
Now the code is NOOP if no `GITHUB_ENDPOINT` is configured.

If it's configured, instead, now the codes assumes that, by DEFAULT, a dependency is hosted on `github.com` so it removes `GITHUB_ENDPOINT` and use `GITHUB_COM_TOKEN` as Github token immediately.
They are restored only if needed, when a dependency is hosted on the provided GithubEnterprise.

This reverts commit 7fcbb47b.

This reverts commit 080d9451.

Closes #1988

This reverts commit f2fb2e6b.