[IndexedDB] Changing the default overwrite behavior of Put

Hey all,

Per the current spec [1], noOverwrite defaults to false for put 
operations on an object store.  Ben Turner and I have been discussing 
changing the default of put to not allow overwriting by default.  We 
feel this is better behavior because simply omitting the flag should not 
result in destroying data.  Putting my application developer hat on, I'd 
much rather have to be explicit about destroying existing data instead 
of having it happen on accident.  We could also change the parameter to 
just overwrite and have it default to false.

What is everyone's thoughts on this?

Cheers,

Shawn