tests/EncodedPolyline: Fixed indent
Format/EncodedPolyline: Added opt_factor parameter to encode/decode()
Format/EncodedPolyline: Change default factor to 1e5

This matches the factors in the other methods and the default of the
original algorithm. Having this set at 1 before can be considered
as a bug.
Do not manage cache when cached tile is on target layer's backbuffer
Avoiding duplicate events
We don't want to re-select an already selected feature
Fixing tests

Selecting the same feature again should not do anything, which was ensured
in the old implementation by a check in the SelectFeature control. This
means that the previous commit causes a change in behavior in standalone
mode, which I would consider a bugfix. I documented this change in the
release notes.