1. undef SUPPORT_TREE_DEBUG_TO_SVG
2. change default tree branch angle to 45 degrees
3. encourage tree neighbors merge faster
4. draw more loops at the top of trees for stronger support
Change-Id: I2edf6a2dddb3b6165c2519ee15e9a7ffaba9de94
(cherry picked from commit 3a9723b2e88a033b3298cd68daf9400265e984a1)