Refactor the code for using a single MongoDB for all graphs
Change debug into trace
Add MongoDBStoreCombineUtil for copying graphs into a single MongoDB database
Calculate the length of a hashed identifier
Minor formating changes
Change default hashIdentifierFlag to FALSE
Do not use hashed values of graph identifiers as default
Merge branch 'singledb'
Add "TESTCSP-REGISTRY" and fix the order of combination index keys
Merge branch 'singledb'
Merge with Markus's latest changes
Add "-sid" options for specifying special graph identifiers
Sync with the main branch, mainly adding the loadWithPrefix() method
Add "-switch" option for switching [@] to [+] in checking graph identifiers
Merge remote-tracking branch 'nzatnsr/master'

Conflicts:
	src/main/java/xdi2/core/impl/json/mongodb/MongoDBJSONStore.java
	src/main/java/xdi2/webtools/mongodb/XDIMongoDB.java