Autoload interactive commands and enable lexical binding

Thanks to @LemonBreezes for implementing the following enhancements in PR #5:

• Autoload interactive commands
• Enable lexical binding

Skip current directory

This release contains a fix that ensures that the current directory is always skipped when searching for a specific parent directory. For example, assume that the current working directory is /abc/def/ghi/abc/. If the user executes eshell-up a then eshell-up will now change to the directory, /abc/, wheres in previous releases it would stay in /abc/def/ghi/abc/.

Add support for peeking

This release adds support for finding a specific parent directory without navigating to it. See the README for examples.