JAVA-422 - Memoize field locations (and other calculated data) for LazyBSONObject
JAVA-422 - Memoize field locations (and other calculated data) for LazyBSONObject

* Intern strings for hopeful (albeit minor) performance boost.

kay-kim/mongo-java-driver,rozza/mongo-java-driver,jyemin/mongo-java-driver,rozza/mongo-java-driver,gianpaj/mongo-java-driver,jyemin/mongo-java-driver,davydotcom/mongo-java-driver,PSCGroup/mongo-java-driver,jsonking/mongo-java-driver,wanggc/mongo-java-driver,jsonking/mongo-java-driver,davydotcom/mongo-java-driver,wanggc/mongo-java-driver