This changes the pilot reading code to always use JSON files for storing
the pilot data. Old pilots are converted to the new format when FSO
starts and after that point only JSON pilots will be used.
startSectionWrite would push unnamed sections on _sectionOffsets, but
endSectionWrite was not removing them, leading to _sectionOffsets
containing tens of unnamed sections when parsing the HUD config.
Pop the unnamed sections in endSectionWrite.
This is a new implementation of the JSON dumping which was already
proposed in #22 but this version tries to allow implementing both
reading and writing JSON files without having to change the existing
code too much. This is done by using an abstract class to hide the
differences between writing the JSON and binary files.
This is currently only capable of writing the files but not reading them
so if the option is enabled all changes to the pilot file are lost. I
will implement reading after this PR has been merged since I would like
to reduce the amount of changes that need to be reviewed.
asarium