emu/push: Add non-functional --force arg
emu/push: Fix --force variable
libemu: Don't cache head() values
libemu: Remove HEAD and parent refs on destroy()
libemu: Only itemize changes if dry-run
libemu: Fix string representation
libemu: Change up symlinking
libemu: Don't print progress info
emu/status: Colourise output
emu/status: Print HEAD ID
libemu: Add --hard-links to rsync flags
libemu: Support multiple link-dest attrs in rsync()
libemu: Use multiple link-dests in backups
libemu: Refactore Snapshot.create()
libemu: Handle errors in Snapshot.create()
libemu: Add missing 'raise' keyword
libemu: Add 'single_arg' prop to Util.parse_stacks()
libemu: Implement Source.checkout()
emu: Add 'checkout' command
emu: Remove obsolete peek and pop commands