Test color-swatches.html

• New `test/color-swatches.html` page with color swatch squares for each of the colors we've defined in LESS.
	» Left half is near-black, right half is near-white.
	» color-swatch styling stolen from the Bootstrap docs.
	» Uses a bunch of LESS tricks to display each swatch in its own color, with its hex code written inside.
• New `less/styles-test.less` for test-only styles.
	» Includes the normal `styles.less`, so everything there is available, and only `styles-test.less` needs to be <link>'d in test pages.
	» #wrapper and #full-back for styling this page.
	» small/.small is used as a small-but-all-caps-readable header.
	» `.make-color-swatches-rules(@colorName)` mixin macros the `.color-swatch` variations for each color, the hex code inside via `:after`, and the color of the small headers.

Also:
• Added a `@body-min-width` var to `main.less` so that `#full-back` can use it.
• Added `styles-test.less` to the gulp.src (now taking an array) in the build-less task.
Added prefixEach helper to Gulpfile

• Wrote a prefixEach() helper function in the Gulpfile, which takes an array of strings (such as filenames) and prefixes them each with another string (such as a filepath).
	» Uses `_.map()`, part of the lodash module, now being required.
	• Added `lodash` to package.json's dev deps.
• Used prefixEach() to make the gulp.src declaration in build-less less repetitive and easier to read.
Added starfield graphics

• Added 4 new starfield graphics (from Steve), all meant to be x/y-repeating but at different intervals, so they form a unique pattern.
Super-minor: 3 blank lines above header comments

• Added an extra blank line (for a total of 3) above each of the header comments in `main.less`.
Added starfield .backs to page

• Added 4 `<div class="back"></div>` elements inside the #sky-phase section, each with a id numbered from #starfield1 to #starfield4.
• Created a `.starfield` class and `#starfield1`-`4` id CSS to set the background-repeat, background-images, and starting opacities (#1 at 25%, #4 at 50%, the others at 0%).
	• Made `.phase` position: relative, and made .back elements directly under it position: absolute with 100% width & height.
		» Pos: relative can cause other layout problems here and there.  So far, this seems to be working fine.  I'll have to keep an eye on it.