Tasks for improved user experience

• Tree operations for deleting/changing blobs (see hesokuri.git/add-blob)
• Logic for merging trees in config database (should go in hesokuri.hesobase)
• Git push/pull logic with custom authorization (uses hesokuri.ssh)
• User interface for configuring (see repl.clj)
• More Hesobase editing commands
• Make app use the new config database for configuration
  • Choose push logic properly based on configuration
• Make app sync and merge the new config database
• Once it's working end-to-end, make newness the default
• Rewrite README.md

hesokuri.source-def:

• host-to-path values may be ignored or empty Strings
• new optional path field: vector of Strings which is relative path from HESOROOT
• unwanted-branches may have hash for each branch

hesokuri.push:

• does pushing - decides itself whether to use git push or custom SSH layer.

hesokuri.config:

• Add a :host-to-key entry which is a map at the top level of the config map (public key Strings)
• :this-host entry, a map with :name (String) and :id (private key) values.

hesokuri.dynamic-config:

• Detects if the config is a flat file or a .git directory, and chooses the config behavior accordingly