Content review sysadmin

[paulcobbaut]

The Sysadmin book now builds, but its content should be reviewed. Some chapters (like networking) are a mess. I will do this for each minibook in the "System Administration" book.

This requires a little bit of work for:
minibook_process_management

A bit more work for:
minibook_local_disk_management
minibook_boot_management
minibook_system_management
minibook_kernel
minibook_backup

A lot of work for:
minibook_networking

[paulcobbaut]

Done:
Part I: Processes
Part II: Disk management

Busy:
Part III: Boot Management
--> need updating init on recent Linux

to do:
Part IV: Systems Management
Part V: Network Management
Part VI: Kernel