Fix UserName and PassWord hard-coded
updated TODO.
fixed the example DB user and DB name.

udoutils ->
ndoutils

Their names are arbitrary. So the previous example is not wrong.
But it is diffrent from what I wanted to use.
Fix default user name of Zabbix.

admin ->
Admin

"Admin" is the strict default user name and it is case sensitive
when you use Zabbix with a certain DB such as PostgreSQL.
Fix conflict pull request
Fix coding style
Remove unused constants
updated the TODO list with issue IDs of GitHub.
Add UnifiedDataStore class to solve confusing VirtualDataStore usage
Fix order of source files
Fix order of source files
Fix typo
Build UnifiedDataStore.{cc,h}
Add wrapper function of getInitialJsonRequest() (Now Test writting stage)
Fix missing double quotation and function type
Fix use g_defaultServerInfo
Add VirtualDataStore{Zabbix,Nagios} to UnifiedDataStore
Add test code of userName and password (Not Passed the test)
Remove needless inheritance
Add UnifiedDataStore::stop() and change start() to virtual.