Unitd

• Added path property in unit status function.
• Added install.sh installation script.
• Removed useless check about path units.
• Added sulogin.unit for single user state.
• Added relative symlinks management.
• Updated README.md.
• Added ulib 4.1.8 dependency.
• Changed stringCopy call according library.
• Replaced memmove with stringCopyN func.