[Patch] Use new checking calls for MapMode.

[michael2402]

Makes tracing bugs easier by checking the consistency of MapMode

​diff, ​patch

Commits:

1. ​4312562: Add consistency checks to MapMode
2. ​2f9583b: Use the new checking calls.

Stats:

 .../josm/actions/mapmode/MapMode.java              | 37 +++++++++++++++++++---
 src/org/openstreetmap/josm/gui/MapFrame.java       | 10 +++---
 2 files changed, 38 insertions(+), 9 deletions(-)

[Don-vip]

I don't like this one. I would prefer to enforce checks in standard calls during next development cycle.

[michael2402]

Then let's leave it.