Adds check_memory which works like check_swap which has been updated to work like check_memory
Both sport a -u(nit) option with MB as default, like their linux versions.
A possible bug with all plugins having the -u(nit) option when using -u kB has been fixed. Don't use icinga to monitor you commodore though.
refs #8287#8060
In their perfdata the plugins will now use absolute values for percentage thresholds.
Also the check_disks output is now more similar to the one of nagios/check_disk.
The README has also been improved.
refs #7886#8060