Cleanup pre-build task

- Use latest Node.js build
- Extract npm directly from stream without writing to disk
- Use proper UpperCamelCase method name
- Misc other improvements
Flatten npm dependencies when extracting

Prevents MAX_PATH errors when building from a long path
Fix URL normalization for Node.js LESS compiler

Unfixes #134 after #153

All unit tests now pass
Add Readme links
Remove old LESS compiler
Merge pull request #194 from SLaks/node-less-fixes

Fix Node.js LESS compiler