PolarSettings: add option "auto bugs"

This feature adds 1% to the bug setting after each full hour after
takeoff (TRAC #1526).
dlgTextEntry: move code to TextEntry.cpp
dlgTextEntry: rename to KnobTextEntry
dlgTextEntry_Keyboard: rename to TouchTextEntry
OLCTriangle: Use a branch and bound method for maximizing triangles
ContestManager: use third trace for triangle solver

The triangle solver needs a more detailed trace to find possible
closed trace loops which respect the 1000 meter rule.
AnalyseFlight: add trace size options