added nsEditProperty
beginning of implementation for SetTextProperties. Currently, it only works if the selection is entirely within a single text node. Currently only
supports bold and italic (mapped to ctrl-b and ctrl-i for testing purposes.)
changed a bunch of interfaces to make things easier, like CreateElement now returns (as an out-param) the element created.
* added DeleteSelection to editor. Doesn't work very well yet because selection is giving me random offsets into text content.
* lots of work in the various transactions.
The key listener is now mostly a mapper of key events to editor actions. Soon, this should be 100% true.
The editor builds transactions that are themselves intelligent. The editor makes very few DOM calls itself.
It relies on the transactions to do most of the actual editing.
