- Read elevation data from external HGT file
- Code cleanup
- Changed icons slightly

git-svn-id: http://svn.openstreetmap.org/applications/editors/josm/plugins@29876 b9d5c4c9-76e1-0310-9c85-f3177eceb1e4
Check for HGT buffer size and data voids.

git-svn-id: http://svn.openstreetmap.org/applications/editors/josm/plugins@29877 b9d5c4c9-76e1-0310-9c85-f3177eceb1e4
Modified icons.

git-svn-id: http://svn.openstreetmap.org/applications/editors/josm/plugins@29878 b9d5c4c9-76e1-0310-9c85-f3177eceb1e4