Store data in SQLite (so that process memory usage does not increase)

[guettli]

If you run viddy for several hours the process eats up all memory.

A SQLite based storage would be great, so that memory consumption does not grow.

An the sqlite file could be shared to other people so that they can have a look at the history, too.

Related: #103

[sachaos]

I've implemented feature to save and load history in viddy v1.0.0-rc.2.
We have been storing results in memory until now, but since we switched to using SQLite, we expect a significant reduction in memory usage. If you encounter any bugs or issues, please let us know.

#117 (comment)

[sachaos]

Viddy v1.0.0 is available now.