Fixes for Gxs msg retrieval:

msgId retrieval fixed, including incorrect stack mtx lock
msgRelatedId retrieval fixed, mem leak removed (did not clean meta)
msg data retrieval fixed 

added related tests 

RsThread::start now initialises mIsRunning to true, needed to unit tear
down on gxs test system.


git-svn-id: http://svn.code.sf.net/p/retroshare/code/branches/v0.5-gxs-b1@5471 b45a01b8-16f6-495d-af2f-9b41ad6348cc

libretroshare/src/serialiser/rsgxsitems.h

@@ -124,6 +124,7 @@ public:
     : RsItem(RS_PKT_VERSION_SERVICE, service, subtype) { return; }
     virtual ~RsGxsGrpItem(){}
 
+
     RsGroupMetaData meta;
 };