lego1: MxVariableTable (#87)

* MxStringVariable -> MxVariable

* cursor test

* GetVariable to 100

* meh

* node insert inline

* move to header file

* use reference to match available code

* variable table init in mxomni, some reshuffling

LEGO1/mxvariable.cpp

@@ -0,0 +1,20 @@
+#include "mxvariable.h"
+#include "mxstring.h"
+
+// OFFSET: LEGO1 0x1003bea0
+MxString *MxVariable::GetValue()
+{
+  return &m_value;
+}
+
+// OFFSET: LEGO1 0x1003beb0
+void MxVariable::SetValue(const char *value)
+{
+  m_value = value;
+}
+
+// OFFSET: LEGO1 0x1003bec0
+void MxVariable::Destroy()
+{
+  delete this;
+}