DatabaseCampaign: abstract campain for interaction with MySQL Database

The DatabaseCampaign interacts with the MySQL tables that are created
by the import-trace and prune-trace tools. It does offer all
unfinished experiment pilots from the database to the
fail-clients. Those clients send back a (by the experiment) defined
protobuf message as a result. The custom protobuf message does have to
need the form:

   import "DatabaseCampaignMessage.proto";

   message ExperimentMsg {
       required DatabaseCampaignMessage fsppilot = 1;

       repeated group Result = 2 {
          // custom fields
          required int32 bitoffset = 1;
          optional int32 result = 2;
       }
   }

The DatabaseCampaignMessage is the pilot identifier from the
database. For each of the repeated result entries a row in a table is
allocated. The structure of this table is constructed (by protobuf
reflection) from the description of the message. Each field in the
Result group becomes a column in the result table. For the given
example it would be:

    CREATE TABLE result_ExperimentMessage(
           pilot_id INT,
           bitoffset INT NOT NULL,
           result INT,
           PRIMARY_KEY(pilot_id)
    )

Change-Id: I28fb5488e739d4098b823b42426c5760331027f8

src/core/comm/TracePlugin.proto

@@ -0,0 +1,30 @@
+message Trace_Event_Extended {
+	// data value read/written
+	optional uint64 data = 5;
+	// register contents
+	repeated group Registers = 6 {
+		// register ID
+		required uint32 id = 1;
+		// register value
+		optional uint64 value = 2;
+		// data register points to
+		optional uint32 value_deref = 3;
+	}
+	// selected stack content
+	repeated group Stack = 7 {
+		required uint32 value = 1;
+	}
+}
+
+message Trace_Event {
+	required uint64 ip = 1;
+	optional uint64 memaddr = 2;
+	optional uint32 width = 3;
+	enum AccessType {
+		READ = 1;
+		WRITE = 2;
+	}
+	optional AccessType accesstype = 4;
+
+	optional Trace_Event_Extended trace_ext = 5;
+}