This is a PR to remove the opinionated lines from the Node.js .gitignore file.
I do not believe that Github's pre-baked .gitignore files should be promulgating opinions, especially in a community that is as fresh as the Node.js community. Questions of what should be checked in should be a decision made on an organization-by-organization basis, or left up to the individual. Github's inclusion of opinion in these files puts unnecessary authority behind that opinion, which can have the negative side-effect of people following without thinking.
These aren't really common patterns in the Node world, and if a Node project includes one of these types as files, they're as likely to want to include them in the project as not (`*.csv` is as likely to be a data source as `*.json`).
This re-covers the http://nodejs.org/api/addons.html case for which the "build" directory was added in 00686415c4, but doesn't break cross-environment projects that use the build directory for including concatenated/minified source. Mazel tov!
The "build" directory is lost in this refactor, as many JS projects
do wish to include a minified/concatenated version of their source
in the "build" folder in source control.
