moved everything into /trunk/ to create the standard svn layout, for use with tools that require this (eg. git-svn). IMPORTANT: do NOT do an `svn up`. instead, re-use your working copy's existing files with `svn switch` (http://svnbook.red-bean.com/en/1.6/svn.ref.svn.c.switch.html).

ch_root, ch_root_via: Documented that these are usually not idempotent operations

Added ch_root_via to transform a map spreadsheet to use a different root, using a connecting root that links the input and output roots together