[pm] added commit() for DB transactions
[pm] added getSessionIPGivenSessionID

for pinpointing which thin client to shutdown given the session ID from
a request coming from Epoptes
[pm] powerdownPoE and 25 sec grace period

the 25 secs was based from the time the UTP cable was connected until
the “penguin” logo begins to appear. This prevents the powerdaemon from
retrieving the IP address of the ThinClient prematurely from the DHCP
lease file when the ThinClient has not booted up yet.
[pm] opening Database via DBhandler(0
[pm] checkAlive and SwitchReady signal handling
[pm][dbhandler] correction on insert function
[pm][mapper] JSON file constructor

new functions for creating a JSON file containing the current thin
clients on the map. Still incomplete without the over-arching function
that will call createSerializedThinClientData(), writeDataToFile(), and
sendJSONDataTORDP()
[pm] addThinClient Modification

now addThinClient() first determines if the thin client object is
previously on DB (by port). If it exists then DB entry is only updated
and not added
[pm]

port 0 is powered-up at the start of  Power Daemon

mapping of new ThinClients is attempted 1 second after a notification
from the switch is received

The next PoE port to be powered-up in the initialisation sequence is
triggered 5 seconds after the last PoE notification was received from
the switch