v7 Exec command and logs enhancements

Changelog

Added exec command

This command may be used to execute any command inside a container. Usage:

ctcli exec <app> <command[s]>

Example:

ctcli exec busybox cat /etc/hosts

Added tail and follow to logs command

It is now possible to follow apps' logs:

ctcli logs -f busybox 

When executed with follow flag, timestamps are outputted.
It is also possible to specify how much of the last bytes would be outputted:

ctcli logs --tail 100 busybox

It is possible to combine these two options

Removed autostart when installing or upgrading release

Hosts file is now mounted from host machine by default