* daca2: Improve package sorting using natsort
This switches the external dependency from semver to natsort, and
improves comparison of packages where one or more of the packages do not
use semantic versioning (major.minor.patch).
This also makes daca2-download and daca2-getpackages work with python 3.
In theory, they should work with python 2 as well, but I have not tested
it.
* Make daca2 scripts executable
* Update hashbangs to python3
* Update usage description
To avoid specifying python version in the usage description, just
show how to execute the scripts and leave the rest to the shebangs.
* No need to specify python version in start_donate_cpu_server_test_local.sh
Leave it to the hashbang instead.
ba33c7f6cd