Resolve symlinks in Module._load

[aleclarson]

Since I have symlinks in the node_modules of many of my local packages, I have altered Module._load to support symlink resolution. This effectively cleans up stack traces when using symlink'd depedencies.

For paths that are neither absolute nor relative:

• require('my-module') → Module._load('my-module', parent, isMain)
• find the package.json nearest to parent.id
• check for symbolic link at path.dirname("path/to/package.json") + "/node_modules"

This PR also includes support for relative imports via the console.

// When entered in the console, it's assumed you mean "relative to process.cwd()".
require('./my-module')

[aleclarson]

After my patches, this all works as intended. LMK what you think. 😁

[aleclarson]

126 provides the "relative imports from console" fix

The symlink-related code is no longer useful. At least with electron@2.x.x, which is all I tested.