Updates for bower-specific folder changes and windows builds (covers things in issue 240)

[mctrusty]

These updates should cover problems brought up in issue 240

I made some updates to build.coffee to point to bower-specific changes (components -> bower_components).

Also made changes to get the build to run under Windows:

1. Added \r to the variable.about.replace regex to handle windows-specific line endings. That character wasn't getting picked up and it would cause the validation step to hang on windows builds.
2. Put conditional in build.coffee to check for windows/non-windows to set the beginning of dir accordingly. I placed the variable isWin in the same location as the other variables to follow that file style and then used it in mkdir to initialize the dir variable. It covers the case apollolux brought up on issue 240.

I also changed the javascript references in tests to point to the new locations so that they would run. I wasn't sure if you were going to phase out qunit testing (and some of those files) -- that's what it looked like from previous changes -- but xregexp (for now, though I believe that changes in 3+) has a reference to qunit so I used it to make those work for the time being.

Last, I added a README.md in the build folder with updated build instructions.

Build now seems to be working for me on Bodhi 2.3 with node 0.8.25 (using node-sass 0.3.0) and node 0.10.12 (node-sass 0.5.0) as well as on Windows7 under node 0.10.

Notes:

• I was originally going to add node-sass to the devDependencies but then found that the build wouldn't work under node 0.8. If I added node-sass 0.3.x instead, the build wouldn't work under node 0.10. So I left it out and just added that information to the build folder's README.md because I wasn't sure if you wanted to maintain support for node 0.8.
• bower won't install anything on node versions pre-0.8. It will give a TypeError: Object #<Object> has no method 'tmpDir' because the os module doesn't include tmpDir until 0.7.11
• There are libraries available (like mkdirp) that might be of use in handling the mkdir functionality in build.coffee. I didn't really want to start adding dependencies and making those changes without some discussion.