Could you please properly document the most important class of this package - Pool

[dejlek]

As the tile says. The most important class of this package, Pool, has constructor with 20+ parameters. Only 3 or 4 of them are covered in the official documentation. Code is almost completely undocumented. Today I was trying to find how to control timeout and retry of failed tasks. I am getting there but with proper documentation it would not take me this long...