LoggerImpl: Removed unused constants

.. and fixed an API comment
Logger[Impl]: Changed LoggerClearFreeSpace() parameter to current_year

This is needed to determine the date for IGC files with the short
filename format. We don't need the entire NMEAInfo struct here.
IGCWriter: Moved simulator attribute to LoggerImpl class

The IGCWriter shouldn't care whether this was simulated or not.
The remaining simulator attributes will also be (re)moved eventually.
IGCWriter: Write I record also in simulator mode

Since the "Fix Accuracy" is mandatory and we write it in any case, we have
to include the I record to make a statement about the format of our
B record extensions.
LoggerImpl: Added GetGPSDeviceName() function
Device/AndroidPort: move buffer to new class BufferedPort

Prepare for making other Port implementations buffered.  This will
solve WinCE SerialPort timing problems.
Device/SerialPort: use BufferedPort

Always keep the receive thread running, and make it feed the buffer.
From there, it may be used by the Read() method.  This reduces the
number of system calls and is a major latency improvement.
ManageFlarmDialog: reimplement as Widget
Driver/FLARM: copy settings code from the Vega driver

The FLARM uses a protocol for setting and requesting values that is
similar to the Vega protocol.
FLARMConfigWidget
data/Dialogs/dlgTarget.xml: Typo in caption.
IGCWriter: Added Log[Empty]FRecord() functions
LoggerFRecord: Renamed detect_f_record_change attribute to update_needed
LoggerFRecord: Removed unnecessary fixed() cast

time is already fixed
LoggerFRecord: Use LoggerFRecord only to detect if new F record is needed
NMEAParser: Only update satellites_used_available if parsed successfully
NMEA/Info: Increase satellite_ids_available expire time to one minute
LoggerFRecord: Added UPDATE_TIME constants
LoggerImpl: Added WritePoint() function
IGCWriter: Moved frecord attribute to LoggerImpl class

The IGCWriter shouldn't have to care about when to write the F record.