Merge pull request #976 from kubark42/pfd-sig-digit-reduction

[PFD]: Reduce significant digits for PDOP.
[Logging]: Removed cruft from plugin.
[Logging]: Cleaned up variable name and scope in order to increase clarity when
adding XML export.
[Logging]: Add support for XML file generation. As per discussion on IRC,
this XML file is generated in addition to the .tll file.