Apply #8166 to master so folks can build a non-empty v2.3.2

This is indeed necessary:
```
bootstrap (master) $ git log -n 1
commit de683e9003b5ec6860a1fcb768416356dd685ef5
Author: Mark Otto <markdotto@gmail.com>
Date:   Thu Jun 13 22:57:05 2013 -0700

    Update README.md

bootstrap (master) $ rm -rf node_modules/
bootstrap (master) $ npm install
[...]
uglify-js@1.3.4 node_modules/uglify-js

hogan.js@2.0.0 node_modules/hogan.js

connect@2.1.3 node_modules/connect
├── debug@0.7.2
├── qs@0.4.2
├── mime@1.2.4
├── formidable@1.0.9
└── crc@0.1.0

jshint@0.9.1 node_modules/jshint
├── minimatch@0.0.5 (lru-cache@1.0.6)
└── cli@0.4.3 (glob@3.2.1)

recess@1.1.6 node_modules/recess
├── colors@0.6.0-1
├── watch@0.7.0
├── underscore@1.4.4
├── nopt@2.1.1 (abbrev@1.0.4)
└── less@1.4.0 (mime@1.2.9, mkdirp@0.3.5, ycssmin@1.0.1, request@2.21.0)
bootstrap (master) $ make

##################################################
Building Bootstrap...
##################################################

Running JSHint on javascript...             ✔ Done
Compiling LESS with Recess...               ✔ Done
Compiling documentation...                  ✔ Done
Compiling and minifying javascript...       ✔ Done

##################################################
Bootstrap successfully built at 11:02AM.
##################################################

Thanks for using Bootstrap,
<3 @mdo and @fat

bootstrap (master) $ cat docs/assets/css/bootstrap*.css
```
**`bootstrap (master) $ # So, the CSS files are empty!!!`**