Utils.cs: remove Esc accelerator binding in our dialogs
Utils.cs: remove Esc accelerator binding in our dialogs

All our dialogs had Escape key bound to the button designated as default
during dialog creation.

However that is:
1) confusing to the user (e.g. Escape could return "Yes" for deletion
   confirmation, which is counter-intuitive);
2) is not flexible - default answer could be and sometimes is redefined
   after creating the dialog in our code, but the accelerator stays the same,
   directly contradicting the new default.
3) rather not bringing any value as keyboard-only management is
   perfectly possible even without that;

So this is now removed. Closes #47.

Signed-off-by: Alex Tereschenko <10ab4a620366487513eb6142e6429449f497066c@gmail.com>

tomboy-notes/tomboy,tomboy-notes/tomboy,tomboy-notes/tomboy,tomboy-notes/tomboy,tomboy-notes/tomboy