Adding the missing pieces

This version adds a few features and improvements that make Butler Spyglass more useful in large Qlik Sense environments. The most notable ones are:

• Added configurable extract length (max number of characters) for each row of lineage data.
• Tweaked log messages, making info-level logging more relevant.
• Add possibility to enable/disable scheduled extraction runs. Opens up for using external schedulers (e.g. cron).
• Add configurable logging to disk. If turned on, the log entries shown on the console are also written to disk.

Full documentation in the repository's readme file.