Merge pull request #8 from Maatts/for-next

WGS84 meters-to-degree calculations, better downloaded area checks, misc fixes
Unify corrections of traced coordinates
Merge branch 'for-next' into development
Remove duplicate nodes earlier in TracerRecord
Merge pull request #9 from Maatts/for-next

Unify common code, LPIS improvements
Avoid decisions between outer ways and multipolygons
Simplify object type checks
Avoid code duplication in ExcludeEdNodesPredicate ctor
Fix infinite recursion in previous commit
LPIS/RUIAN: unify createTracedEdObject code
RUIAN: move retrace geometry functions to a class
LPIS: add multipolygon retrace support
Remove unused imports
LPIS: tune connect/cleanup tolerancies
RuianLands: fix missing village_garden retrace pattern
RuianLands: cleanup RuianLandsRecord
Fix: detect and ignore obscure multipolygons
Disallow retrace if it orphans an important node
Detect invalid input ways in TracerRecord
RUIAN: Don't ignore RuianServer exceptions, free resources