## [why]
`std::env::current_exe()` has platform dependent behavior and will often
return the target binary, not the symlink name, when the binary is executed
via symlink. So, to support symlinking, the first (0th) arg from `std::env::args()`
is used, when possible, with fallback to `std::env::current_ext()` if args are
missing or empty.
- ref: <https://github.com/rust-lang/rust/issues/43617>
- final multi-binary will now function correctly with any binary/executable name
- multi-binary container acts as the specified util IF EITHER ...
1. the binary/executable name exactly matches the name of an applet/util
2. the binary/exectuable name matches <PREFIX><UTIL_NAME> pattern
* where the PREFIX is any string ending in a non-alphanumeric character
