Added zpool io stats
This version is unstable
Poolname included in settings
Major bugfix
Parsing settings file:
Due to an unknown reason, there was placed some vague text(?O??7) at the first positions in
the char arrays where the XML key-value pairs were stored in. This caused a malfunction when
starting the program with an exising settings.xml file.
v1.2 Development Release
Added some IO stats attributes:
- read & write operations
- read & write bandwidth

Bugfixes:
- Parsing of the settings.xml failed, which resulted in a runtime error and caused the program to exit.

Only tested on OpenIndiana build 151a7.
v1.2 Development Release
Updated the README
v1.2 Beta
Added the following statistics to the collection of a zpool:
- checksum errors
- state
- space
- space allocated
v1.2 Beta bugfix
Bugfix
Fixed the bug where the program left a zombie process after every wait().
It seemed this was caused due to not closing the file stream from popen().
v1.2 Stable
- Fixed the bug where after a certain time, zfs-stats was unable to open the libzfs
handle.
- Now zfs-stats is also collecting diskspace(alloc & free), checksum errors and the
zpool vdev state