Adding native `bcrypt` to a project may require build tools be available on the system. This commit adds a note about that, and a link to the node-gyp documentation that best explains which tools to install. For more details, see this issue: https://github.com/meteor/meteor/issues/10113
I had to scrap the 1.4.2-beta.8 release because meteor-tool@1.4.2-beta.8
got published by a partial run of the publish-release script, but then the
publish-release script thought meteor-tool changed after that, and I
didn't want to republish it as something like 1.4.2-1-beta.8.
According to the README, this implementation is approximately 2.7 times
slower than native: https://www.npmjs.com/package/bcryptjs
Apps that wish to continue using the native bcrypt package should run
`meteor npm install --save bcrypt` in the root application directory, and
the npm-bcrypt package will prefer that implementation.
