This avoid that we have to chek the type in the getter.
Also update the comment - we need the strip since the readline call
will not strip the newline.
COL_MESSAGE contains the message offset as an internal optimization. When
preparing a row for filters, we need to replace this. Otherwise filters
get an 'int' instead of the 'string' they expect.
This is the step where the timeline graph gets colored with the individual log
level colors. It's roughly 4.5 times faster now. Probably can be made even
better, the code also needs a cleanup.
RangeFilteredLogModel is gone. The functionality is trivially implemented in
FilteredLogModel now. Changing the range is now O(log n) at worst (was O(n) at
best, for rewriting the arrays). Stacking filtered models is not supported
anymore, which simplifies the code.
