* 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
Some interesting results:
* Minor simplification of PQ converters and unit ctors; may not seem like much, but I think it enables possible future simplifications of a similar kind.
* CMeasurementPrefix is gone, no longer needed. Now prefixes are applied at the template stage.
* Apart from that, PQs public API is unchanged.
* Discovered that ft/s^2 conversion factor was wrong: fixed.
* Default unit is more clearly stated in one place, not restated in many different places, and is not always the SI unit
* Converter strategy pattern in CMeasurementUnit, covering linear, affine, and different kinds of sexagesimal units
* General reorganization of CMeasurementUnit construction and CPhysicalQuantity methods, not removing any behvaiour
* Move duplicated method unitFromSymbol from derived classes into base class CMeasurementUnit
* For DBus, CPhysicalQuantity marshals both in its own unit and in the default unit
