Be more strict about type conversion:

* numbers are no longer auto converted to booleans, use to_boolean or != 0
  * booleans are no longer auto converted to numbers, use to_int
  * strings will soon no longer be auto converted to numbers, use to_int

Added version information ("since 0.3.7") to documentation

git-svn-id: svn://svn.code.sf.net/p/magicseteditor/code/trunk@1006 0fc631ac-6414-0410-93d0-97cfa31319b6

src/script/dependency.cpp

@@ -78,6 +78,7 @@ class ScriptMissingVariable : public ScriptValue {
 	virtual operator String() const { return wxEmptyString; }
 	virtual operator double() const { return 0.0; }
 	virtual operator int()    const { return 0; }
+	virtual operator bool()   const { return false; }
 	virtual ScriptValueP eval(Context&) const { return script_nil; } // nil() == nil
   private:
 	String name; ///< Name of the variable