Release Candidate 1 for wdi5 0.9.0

[vobu]

after two alphas, we've published a RC1 today!

most notable changes:

• provide the majority of all UI5 control selectors/locators that UIVeri5 supported and that OPA5 provides
  → there are still some issues to iron out or add respectively
• allow for a custom logging "tag" (wdi5.getLogger("custom-tag").success("yay!"))

lots of added documentation, specifically on the locators, including code samples over at
https://js-soft.github.io/wdi5/#/locators