sysstat 2.0p1: new output formatting and meter handling
   - replaced previous optarg-based argument parser with one from Boost libraries
     looks better and is easier to handle
   - replaced whole system of output generation, now, instead of having only control
     on what is displayed by setting display flags, user can insert his own string
     in which the %-preceded formatters will be replaced by values
   - Objects for monitoring varoius system stuff now are generated only if % formatter
     is detected. Example, if formatting string is "%C" only cpu meter will be generated
     and information needed for other meters (swap, ram, battery) will not be gathered
   - Added system detection in CMakeList.txt. Right now it will be throwing only messages
     but in the future it can be used to set system-specific stuff. This is a preeliminary
     to adding OS X and BSD support in the future.
updated README to reflect program changes