v0.29.0

Fixes

• Protect against cat clobbering in nvm alias (#858)
• Fix nvm ls when $NVM_DIR has spaces in it (#861)
• Make sure nvm debug doesn't use an overridden sed
• nvm exec: don't fall back to .nvmrc when the provided version is not installed

Enhancements

• Ensure nvm use output shows up after prefix check passes
• [installing] echo the URL that the tarball is being downloaded from
• nvm run: use common code path for "ensure version installed"
• Use xz tarballs if available (#823)
  • This saves ~25% bandwidth while downloading node installers for io.js v2.3.2 and later, and node v4.0 and later.

Documentation

• indicate that the install script is also for updating (#859)