Continued work on dynamic encoding #284

[Kittyfisto]

Continues #41 Continues #284

• Fixed bugs in StreamingTextLogSource
• Introduced BufferedLogSource to cache log entries and to fetch them asynchronously
• Allowed more fine grained control over which data is stored, fetched from and asynchronously fetched to the cache (for now, only the display uses the cache, the rest streams from disk)
• Renamed LogColumns to GeneralColumns
• Moved spezialized columns to their corresponding log source
• Introduced Attribute to mark methods intended to be thread-safe
• Introduced LogSourcePropertyAdorner to calculate properties' values based on the underlying data (such as Start/End time)

Any expected problems concerning backwards compatibility of existing plugins?

Yes

Any expected problems concerning backwards compatibility of existing user settings?

Yes/No

Does this break existing user workflows?

Yes/No