new producers manager class

this manager collects all Producer objects and being a singleton it decouples
producers management from the Needs manager to make it easier to 
observe and display informations about producers agents
replaced internal collection by Producers in Needs
replaced Needs by Producers
added property for NeedUnit object and renamed fields for clarity
specified that remove should occur on first item
removing needs at different steps than before (earlier)
added new "mester" chart showing instant values of important counters
added zooming feature using giCentre ZoomPan class
increased window height, made window resizeable
improved zooming with increased framerate, and disabling click-drag zoom
new getters to fetch rserved resources amounts
new getter to fetch reserved supply amount
cleanup and renaming of variable, cleaned up panning
get reserved amounts for resources and supply
added getter to count total of active agents
fetching agents data
changed framerate, increased charts length
changed charts init to allow custom colours
added title to master chart
changed wording and plotted values replaced by more meaningful values