prepapre for index2d
entrySet for DBOject
Merge remote-tracking branch 'github/master' into index2d

Conflicts:
	src/main/java/com/foursquare/fongo/impl/Util.java
	src/test/java/com/foursquare/fongo/FongoIndexTest.java
Merge pull request #68 from twillouer/index2d

Handle 2d index ONLY for creating them, not for used