microsimulation-class: A microsimulation object
In sms: Spatial Microsimulation

It holds all microsimulation details and objects such as data, results etc.

`census:`	A census data.frame where each row contains census information about a geographical area
`panel:`	A data.frame containing the individual based records from a panel survey. Those data will be fitted to small area contrains and will populate each vrtual area.
`lexicon:`	A data.frame containing the association of columns between census data and panel data. Each row contain a conection between census and panel data.frame.
`resuls:`	A list of results from the fitting process.
`iterations:`	The number of itertions until th end of the fitting process.