Adjusted design to only use one result stream.

That way, generator results can be handled by the aggregator, which is the way it should be.
Verify and Seal adjusted to deal with the new type of info.
Unified errors to allow aggregators to deal with them correctly.

Verify now has a chance to produce much better results, however,
the current implmenetation still lacks precision.
Slight improvements to verify result printing.

It shows we really want to associate a reesult with the index that
triggered it, but it can't be done with the current data structures
Minor memory allocation improvements.

After some profiling, it showed that the buffer isn't needed in aggregation of seal.
The gather reader will also pre-allocate a read-buffer, previously a rather large
object was allocated for each file to be read - it now is much smaller due to the
external buffer, further reducing heap pressure.
Minor fixes with huge effect

Logging of seal was somewhat broken, and verify couldn't deal with relative paths (and more)
Improved top-level readme file and reorganized ToC
Now it's possible to hash one or more files.

It will be smart enough to detect containment, merging inputs accordingly.
Also it works natively with seal and sealed copy.
Moved seal owned parseSources into a shared space to allow verify to benefit.

There was a bug due to verify not using the same function, and I remember
having thought about it when I wrote it ... .