default extension fix
Added a new example graph with sparse node ids (max node id is 90M)
Merge pull request #78 from szymonm/extensionFix

default extension fix
Benchmark reading from adjacency list
Sample adjacency list graph

Facebook graph stored as adjacency list in 4 chunks.
Yourkit usage acknowledgement
Merge pull request #82 from szymonm/yourkitAck

Yourkit usage acknowledgement
Modified yourkit acknowledgment text.
Minor edits to README
Merge pull request #79 from szymonm/benchmarkReadingAdjecencyList

Benchmark reading from adjacency list
Map based NodeNumberer
assert to log.error when wrong input
log.error to exception
Merge pull request #81 from szymonm/hashArraysBasedNodeNumberer

Map based NodeNumberer
GetNodeById benchmark
Merge pull request #86 from szymonm/randomWalkBenchmark

GetNodeById
Minor change in README
Fixed test graph location.
Remove unnecessary semicolon
Fix typos in the documentation