getTableStatistics( $changesMap ) → \$statistics
Creates a 'statistics' hash that shows the result of applying changes to the 
EditTableData object: 
-  {rowCount} : the total number of rows, including header and footer rows
  -  {added} : the added rows
  -  {deleted} : the deleted rows
  -  {bodyRowCount} : the number of body rows
 
 
StaticMethod _mergeHashes (\%a, \%b ) → \%merged
Merges 2 hash references.
StaticMethod createTableChangesMap( $paramString ) → \%map
Parses the paramString to a hash.
paramString can contain a list of key-value pairs using the structure (rowNumber_1=rowState_1,rowNumber_2=rowState_2,...), for example:
 
-  =0,1=0,2=1
 
 
Row states are: 
-  -1 
 -  row deleted
  -  0 
 -  nothing changed
  -  1 
 -  row added
  -  2 
 -  reset (no action)
 
 
Not all rows have to be present in the param.
StaticMethod tableChangesMapToParamString( \%tableChanges ) → $paramString
In the reverse operation to createTableChangesMap, converts a tableChanges hash to a param string.
For example, 
{
	'0' => '0',
	'3' => '1'
}
will be converted to:
'0=0,3=1'
StaticMethod _getTableChangeStatistics