Improve UI for selected keywords in Taxonomy Selector

[jpitts]

The current UI for selected keywords is rudimentary and not based on designs.

Use this recent screen shot of designs being tested:

In this design, the selected keywords are more compact than the current implementation on staging, have coloring, and also do not indicate hierarchical placement.

[jpitts]

Work on the taxonomy selector improvements is happening on this branch: https://github.com/designforsf/brigade-matchmaker/tree/ui_update

[jpitts]

Some fixes after looking at what @alschmiedt has committed:

• Use common naming for skills, learnSkills, interests (right now they are named Skills, Learnings, and Interests). This will make it easier to access in other components.
• Implement getSelection() which would return JSON in the format of https://github.com/designforsf/brigade-matchmaker/blob/master/docs/taxonomy.md#tree-structure-for-ui-rendering . This is necessary to run the matching function from what the user has entered into the taxonomy selector.
• Implement indicateMatchingStarted() and indicateMatchingFinished() callbacks. This will enable the ui_update component to reflect changes in the main client and perhaps even in other components.

I'll open it up and see if I can implement these tomorrow morning.