Renamed VariableSymbol to ParameterSymbol, introduced layer variable...

Renamed VariableSymbol to ParameterSymbol, introduced layer variable declarations and changed IOSymbol to VariableSymbol which now combines IO variables and layer variables
Status Job ID Name Coverage
  Windows
passed #428931
Windows10
masterJobWindows

00:01:27

 
  Linux
passed #431405
BranchJobLinux

00:03:26

failed #428932
BranchJobLinux

00:01:05