.travis: go back to using the "os" block

I got the "Multi-OS beta feature" enabled for this repo on Travis-CI.
Revert ".travis: go back to using the "os" block"

This reverts commit eb23fa86deb7d7043f37113f2e4f7ea50a02c443.

While "osx" mode now works with the NodObjC repo, `nvm` is not
installed on the OS X test boxes at this time. I'm working with
the Travis-CI support team to get that fixed.
test: OCD styling tweaks to memtest.js
test: move "memtest.js" to `archive` for now

It's failing on node v0.6 and v0.8 for some reason.
@trevlinton hopefully you can take a peek and see what's going on.
examples: lint
test: lint
examples: re-compile "Test Framework.framework"
examples: return 13 in example

Just for clarity.
examples: add gyp build instructions for "Test Framework.framework"
test: add reference to original issue
package: downgrade version number again

I wasn't ready to bump this...
Integrated changes from master