Add frost-fixed-table component

[job13er]

This project uses semver, please check the scope of this pr:

• [ ] #patch# - backwards-compatible bug fix
• [x] #minor# - adding functionality in a backwards-compatible manner
• [ ] #major# - incompatible API change

NOTE: I'll be adding support for custom cell renderers today, but I wanted to get this out at least first.

CHANGELOG

• Added frost-fixed-table component which allows for frozen left and right columns and a fixed header row, but relies on fixed column widths/heights to work properly.
  • Updated ember-frost-core
  • Updated existing components to derive from frost-component now.

[coveralls]

Changes Unknown when pulling e338ef99b6885c5c28c780d3481069ceddea9f43 on job13er:add-fixed-table into on ciena-frost:master.

[coveralls]

Changes Unknown when pulling e338ef99b6885c5c28c780d3481069ceddea9f43 on job13er:add-fixed-table into on ciena-frost:master.

[TheOtherDude]

LGTM!

[job13er]

Approved