Updated docblocks to match reality

Some docblocks where missing, others incomplete or plain wrong. Little change in code.
Comments: change params from int -> float

The default may be 1, but the parameter can be a float and the tests
cover that.
Merge @netzkind/patch-1 (#4) into master

Updated docblocks to match reality

Some docblocks where missing, others incomplete or plain wrong.
Especially increment/decrement did NOT accept arrays, despite the
docblock making us think they do.

Only very little change in code.