HtmlTag: first steps

WAY-81
Merge pull request #7 in WAY/way-ui from WAY-81-markupelement-htmlelement-p to master

* commit '5b9ebe11480221e2ef56550d26fd01de22c58fe2':
  HtmlTag: first steps
HtmlTag + attributes

WAY-82
Merge pull request #8 in WAY/way-ui from WAY-82-htmltag-attributes to master

* commit 'ae2e04a9d4a7640ee8d5232c9bab9734ddcc8ed9':
  HtmlTag + attributes