Fixed human_readable + usage + stuff
check_meminfo: fix performance output

To prevent errors like:
  "Can't convert '0,' to a floating point number."
Zero values are now printed as "0.0" instead of just "0".
Merge remote-tracking branch 'credativ/master'

Conflicts:
	Makefile
	include/icinga.h
	plugins/check_meminfo.c
	plugins/check_procstat.c
	templates/check_meminfo.php