Add UnifiedDataStore class to solve confusing VirtualDataStore usage
Fix order of source files
Fix typo
Build UnifiedDataStore.{cc,h}
Add VirtualDataStore{Zabbix,Nagios} to UnifiedDataStore
Remove needless inheritance
Add UnifiedDataStore::stop() and change start() to virtual.
Replace VirtualDataStore{Zabbix,Nagios} in ExecContext and FaceRest with UnifiedDataStore
Also ItemInfoList should be fetched via UnifiedDataStore.

Sorry, I forgot to replace it at project-hatohol/hatohol@4e907f0.
Add a test case for UnifiedDataStore
Add "format" attribute to StringUtils::sprintf().

Currently we don't support compilers which don't have this
extension.
Althouth glib has more pretty macro "G_GNUC_PRINTF", we don't use
it at here because MLPL doesn't depend on glib.
Call tzset(3) before reading timezone to make sure to initialize it
Use testTriggerInfo as expected value of testUnifiedDataStore::test_getTriggerList.

Since I've noticed that currently this test should be same with
testDBClientHatohol::test_testGetTriggerInfoList, I use same
expected data at this time. On the other hand these implementations
may become different in the future because VirtualDataStore* may
have other data sources (such as on-memory data). So I leave this
test.
Remove needless include
Set suitable DB path for testUnifiedDataStore.

We should set the path of DB_DOMAIN_ID_HATOHOL for testing
UnifiedDataStore, not DEAFAULT_DB_DOMAIN_ID.
In addition we use fixtures/testDatabase-hatohol.db for testing it
since currently UnifiedDataStore is read-only.
Add a test for UnifiedDataStore::getEventList()
Add a test for UnifiedDataStore::getItemList()
Merge branch 'unified-data-store'

Conflicts:
	server/src/Makefile.am