[Core] PascalCase component names, reorganise directory structure

[mbrookes]

• PR passes current tests, docs demo, and is linted.
• Commit and PR titles begin with [ComponentName], and are in imperative form: "[Component] Fix leaky abstraction".
• Description explains the issue / use-case resolved, and auto-closes the related issue(s) (http://tr.im/vFqem).

Reorganise and PascalCase component names. Incorporates #3682.

With some additional work on our build process to publish from within lib (and updating the docs site build so the examples have matching paths), this PR substantially addresses #2679.

Closes #3670, closes #2970.

(#2697, Rename of LeftNav to follow in a separate PR).

[nathanmarks]

@mbrookes

These need to go in src/Card/

https://github.com/callemall/material-ui/tree/e6b7ca0850be4aed076aea5b993272cc38741520/src/card

[mbrookes]

Thanks, yes, they were already locally - it was more a question of getting git to recognise directory name changes so that the remote is correct.

There were a bunch of others, but I've finally got it to play along. 😄

[cgestes]

@mbrookes would this config of git helps:

git config core.ignorecase false

[mbrookes]

@cgestes - thanks, yes, it might well have done if I'd set it before starting this PR. 😄

[nathanmarks]

Looks good to me 👍

@mbrookes This was fun to debug 😄 oh git oh git...