refresh formatting
MANTA-17 reviewed merge to master, temporarily disabled features pending disccusion
MANTA-33 hide edge count behind a getter
MANTA-33 hide node count behind a getter/setter
MANTA-33 make node edges private
MANTA-33 put node count under mergeEdge control
MANTA-33 eliminate count from SVLocusNode
MANTA-33 switch edge count to smaller data type
MANTA-33 reduce memory during candidate generation

reduce memory by skipping graph index generation, add extra
graph check step to make sure graph is well-formatted before
starting candidate generation
MANTA-33 hide node interval and evidence-range
MANTA-33 use lightweight obs to reduce graph memory

Replaced blt_util observer class with flyweight_observer to
reduce memory of singleton loci, at the cost of much uglier code.
MANTA-33 minor tweaks from test run
MANTA-33 major redesign of how node edges are stored

this is intended to save space when the graph is represented
and indexed in ram
MANTA-33 refresh format
MANTA-33 setup default task memory requests