Upgrading to latest roaring.
Merge pull request #5 from lemire/master

Upgrading to latest roaring.
Upgrading roaring to version 0.4.3 (but fix release)
Merge pull request #6 from lemire/master

Upgrading roaring to version 0.4.3 (bug fix release)
Merge branch 'master' into cleanup-roaring
separate benchmarks for different bitmap structures