[Merkaartor] Release notes

[bvh]

For 0.11 I feel we need to mention the following two things in the
release notes since they may surprise people (it suprised me)

- if you use merkaartor on areas with substantial imported material
  (from AND or TIGER like the Netherlands or USA), each node has at
  least two tags related to that import. Hence merkaartor will higlight
  them with the Information icon. Since this icon appears on every node,
  editing is basically impossible. You can turn these icons of in the
  style editor (last two items uncheck the icon)

- on start up the screen will be covered with a red dot pattern showing
  the areas where you have NOT downloaded data from the server. This is
  intentional to raise awareness to the user that there might be data
  there on the server that is not shown.

Anyone else has suggestions of things that we should mention because it
could present a surprise?

cu bart