fend 1.3.0

Version 1.3.0

on Rust Cargo

Changes in this version:

• Support loading exchange rates from the UN treasury, which supports more currencies than the European Central Bank. This can be configured via the new exchange-rate-source option. (by @Markos-Th09)
• Exchange rates are now available in fend-web (by @Markos-Th09)
• Support complex numbers in many more situations, including trigonometric functions, logarithms, exponentiation, etc. (by @Markos-Th09)
• Add support for unit prefixes for parsecs (e.g. Mpc)