Much better version of Knuth's elevator. This seems to have the same results as the trace in his book, modulo bugs in the book and (presumably) my implementation.

Modified some aspects of the elevator example. The elevator itself is not fully following the spec yet.

Added retry-option to work around occasional failure while checking out git repo due to race condition.

Removed unnecessary unsafe blocks and fixed a bug related to adding invalid sample values to `Utilized` random variables.

Minor changes to the README, changed dependencies to ODEM-rs crates in Cargo.toml to be able to develop them independently.

Profiled and improved performance of the event calendar. Made it private in order not to commit to early.