fix data race in tests by not starting a goroutine for each log line

Handlers can take some time to run, and it's expected that after
Server.Wait() returns the handler has already finished executing.

Also if a handler needs to process log lines concurrently it can start
a goroutine itself.

The following data race was triggered by tests:

==================
WARNING: DATA RACE
Read by goroutine 20:
  gopkg.in/mcuadros/go-syslog%2ev2.(*ServerSuite).TestTailFile()
      /Users/cezar.sa/go/src/gopkg.in/mcuadros/go-syslog.v2/server_test.go:43 +0x283
  runtime.call16()
      /usr/local/Cellar/go/1.4.2/libexec/src/runtime/asm_amd64.s:401 +0x44
  reflect.Value.Call()
      /usr/local/Cellar/go/1.4.2/libexec/src/reflect/value.go:296 +0xd8
  launchpad.net/gocheck.func·006()
      /Users/cezar.sa/go/src/launchpad.net/gocheck/gocheck.go:733 +0x51d
  launchpad.net/gocheck.func·004()
      /Users/cezar.sa/go/src/launchpad.net/gocheck/gocheck.go:628 +0xf7

Previous write by goroutine 24:
  gopkg.in/mcuadros/go-syslog%2ev2.(*HandlerMock).Handle()
      /Users/cezar.sa/go/src/gopkg.in/mcuadros/go-syslog.v2/server_test.go:85 +0x36

Goroutine 20 (running) created at:
  launchpad.net/gocheck.(*suiteRunner).forkCall()
      /Users/cezar.sa/go/src/launchpad.net/gocheck/gocheck.go:629 +0x544
  launchpad.net/gocheck.(*suiteRunner).forkTest()
      /Users/cezar.sa/go/src/launchpad.net/gocheck/gocheck.go:765 +0xf2
  launchpad.net/gocheck.(*suiteRunner).runTest()
      /Users/cezar.sa/go/src/launchpad.net/gocheck/gocheck.go:770 +0x3f
  launchpad.net/gocheck.(*suiteRunner).run()
      /Users/cezar.sa/go/src/launchpad.net/gocheck/gocheck.go:584 +0x3aa
  launchpad.net/gocheck.Run()
      /Users/cezar.sa/go/src/launchpad.net/gocheck/run.go:76 +0x57
  launchpad.net/gocheck.RunAll()
      /Users/cezar.sa/go/src/launchpad.net/gocheck/run.go:68 +0x132
  launchpad.net/gocheck.TestingT()
      /Users/cezar.sa/go/src/launchpad.net/gocheck/run.go:56 +0x582
  gopkg.in/mcuadros/go-syslog%2ev2.Test()
      /Users/cezar.sa/go/src/gopkg.in/mcuadros/go-syslog.v2/server_test.go:13 +0x35
  testing.tRunner()
      /usr/local/Cellar/go/1.4.2/libexec/src/testing/testing.go:447 +0x133

Goroutine 24 (finished) created at:
  gopkg.in/mcuadros/go-syslog%2ev2.(*Server).parser()
      /Users/cezar.sa/go/src/gopkg.in/mcuadros/go-syslog.v2/server.go:196 +0x1bb
  gopkg.in/mcuadros/go-syslog%2ev2.(*Server).scan()
      /Users/cezar.sa/go/src/gopkg.in/mcuadros/go-syslog.v2/server.go:163 +0x146
==================

Author: cezarsa

server.go

@@ -202,7 +202,7 @@ func (s *Server) parser(line []byte, client string) {
 	logParts := parser.Dump()
 	logParts["client"] = client
 
-	go s.handler.Handle(logParts, int64(len(line)), err)
+	s.handler.Handle(logParts, int64(len(line)), err)
 }
 
 //Returns the last error