2.4.0

Fixes and improvements in release 2.4.0:

• fix #147: implemented logging image status of client.
• more english translations of console messages and further code beautifying.
• fix #141: linbo manipulating the local start.conf when finding labels with same name.
• fix #142: added start.conf examples for Ubuntu 20.04 with correct kernel and initrd paths.
• fix #139: improved error handling in linbo_wrapper, linbo_cmd and linbo-remote.
• fix #146: PID of screen launched (lmn7 only).
• fix #148: linbo-remote, handling of clients with dynamic ip (lmn7 only).
• fix #149: linbo_gui on demand.
• fix #150: Additional grub menu option "Start with Linbo".
• minor linbo grub theme improvements.
• fixed kernel and initrd paths and linbo menu class in remaining grub config templates.
• fix #153: Extend linbo clients ssh authorized_keys.
• fix #152: Linbo should not reboot on update in all cases.
• fix #154: New linbo_gui (lmn7 only).