Components resolvers

[sheerun]

This is meta-issue regarding components resolved.

We need to support all bower resolvers:

• Fs (supports only exact or * versions)
• GitFs (checkouts version from filesystem git repository)
• GitRemote - clones repository first, before using GitFs
• GitHub - tries to download github archive first
• SVN - clones svn repository and checkouts tag
• URL - supports number of archive formats before using Fs

All resolvers could have form:

class Resolver
  # @param source [String] the source location
  # @param destination [Pathname] where to save component
  def call(source, destination)
  end
end

Questions:

1. How to handle logging
2. How to handle testing