fix(interimElement): make cancel and hide not fail when no element is shown
feat(subheader): add subheader component with sticky scroll

Closes #216. Closes #269.
style(sticky): remove deprecated css
style(sticky): simplify css rules
perf(sticky): display: none non-adjacent sticky headers
fix(textfields): match float-label (light theme) specifications
style(sticky): remove repeated style rule
demo(subheader): fix demo
update(textfield): refactored demo, updated jsDocs, added README
update(textfield): removed explicit usage for `fid` in demo html
update(textfield): improved support for `disabled` attribute

Demo shows how <tf-float> elements will not only be disabled but also will skip tab focus.
update(demo): TextField demo shows fields grouped on rows

Enhanced `$tff-` styles also
update(demo): TextField demo shows how to change input width
update(textfield): improved dashed line rendering for disabled text inputs
refactor(sticky): put sticky elements as siblings of content
update(textfield): improved dashed lines
update(textfield): propagates `type` settings
feat(circular_progress): Add circular progress component

This commit adds a new component, material-circular-progress, which enables the use of both determinate and indeterminate circular progress indicators.

Fixes Issue #192
Closes #365
feature(bottomSheet): add bottom sheet

Closes #277
Closes #369
feature(bottomSheet): add bottom sheet

Closes #277
Closes #369