API modifications, remove blockchain defaultGroupId, Eclipse/git

GET /assets/trades/recent expanded to allow multiple otherAssetIds

When GET /assets/balances is called with address(es) but no assetIDs
then it will return balances for all assets, including zero balances
for assets the addresses don't own.

GET /addresses/{address} no long fakes a default groupID - in fact
defaultGroupId now removed from blockchain config.

Some Eclipse IDE files now hidden/removed from git repo.

.gitignore

@@ -5,3 +5,7 @@
 /arbitrary*
 /Qora-BTC*
 /.factorypath
+/.settings*
+/.classpath
+/.project
+/log4j2-test.properties