various edits

- Added \lib\sass\partials\_media-queries.scss with base media query
structure (props to Chris Coyier)

- Added \lib\sass\_custom-style.scss

- Created _inline-styles.scss and added some basic classes.

- Added box-sizing polyfill for basic grid compatibility in older
browsers (only called on element .columns)

- Added html5shiv.js

- Cleaned up "_mixins.scss" > @mixin animation to only support -webkit-
prefix and no-prefix (standards compliant) animation properties. Prefixr
plugin was incorrectly adding non-existant -prefixes-.

- Added $user_agent variable definition from ARRAY $gb in
lib\php\functions.php

- Made a few adjustments to variables in \lib\php\functions.php

- Structured a few example copy and grid layouts in \index.php

- Added conditional comment HTML tag support in \_header.php,