Send attribute configuration event to all clients after device restart

[mliszcz]

Fixes #361

[mliszcz]

 5/93 Test  #6: CXX::cxx_dserver_misc .............***Failed   19.65 sec
Starting DevTest/test
DevTest/test PID: 5680
Starting FwdTest/test
FwdTest/test PID: 5699
Running 8 tests
Testing DServer Misc :

	State and Status commands --> OK
	DevRestart command on the dserver device --> OK
	DevRestart command on classical device --> OK
	str = The device is ON
The polling is ON
	name description state ans status CORBA attributes --> OK
	ping the device --> OK
	info call --> OK
	event subscription recovery after device restart --> OK

In DServerMiscTestSuite::test_attr_conf_change_event_after_device_restart:
/home/tango/src/cpp_test_suite/cxxtest/include/../../new_tests/cxx_dserver_misc.cpp:285: Error: Expected (2 == callback.num_of_all_events), found (2 != 1)
TEST FAILED in:
1 iteration of test case
1 iteration of test suite

[bourtemb]

Thanks @mliszcz for the fix and for removing some duplicated code.
This seems to work as expected.
I just propose a small improvement in a comment.