eZ Publish Platform 5.4.11 release

Done:

• Bump ezpublish-legacy's lib/version.php to 5.4.11
• Tags releases:
  https://github.com/ezsystems/ezpublish-legacy-ee/releases/tag/v5.4.11-RC1
  https://github.com/ezsystems/ezpublish-kernel-ee/releases/tag/v5.4.11-RC1
  https://github.com/ezsystems/ezplatform-solr-search-engine/releases/tag/v1.0.10-RC1
  https://github.com/ezsystems/ezstarrating-ls-extension/releases/tag/v5.3.2
  https://github.com/ezsystems/ezfind-ee/releases/tag/v5.4.11-RC1
• Meta repo tag https://github.com/ezsystems/ezpublish-platform/releases/tag/v5.4.11-RC2

Doc on release notes, we'll need to document in the release notes the following security improvements for people upgrading:

• Meta repo security changes https://github.com/ezsystems/ezpublish-platform/compare/v5.4.10...5.4