* INetwork setOwnAircraft slots
* ATIS received shimlib callback triggers separate VoiceRoom and LogoffTime signals
* INetwork statusMessage signal emitted in response to shimlib errors
* INetwork::ConnectionStatus added a DisconnectedError value and toString conversion
* INetwork::isConnected method
* Argument in CNetworkVatlib constructor to enable stealth or observer mode
* Update CLI sample, tests, and CContextNetwork accordingly
* rename CStatusMessages to CStatusMessageList
* rename NetworkVatlib to CNetworkVatlib
* replace all occurrences of Realname with RealName (correct camel case)
* CSequence method corresponding to CList::append is push_back
* don't compile the qdbuscpp2xml metadata plugin by default
* CAircraftIcao string members always trimmed and capitalized
* added CComSystem::roundTo25KHz
* using epsilon comparison in a couple of places
refs #81
Added externals.pri looking for the external headers/libraries in 3 steps:
1. Manually set absolut path. Currently commented. Uncomment for local
use.
2. Enviromental variable "VATSIM_EXTERNAL_DIR"
3. default path client/externals.