First pass on the logs

The newly-added logs manage a list of messages. Entities do register a
message to it when hitting each other. Display is created, but not yet
added to the layout actually displayed.

squirrelbattle/display/logsdisplay.py

@@ -0,0 +1,17 @@
+from squirrelbattle.display.display import Display
+from squirrelbattle.interfaces import Logs
+
+
+class LogsDisplay(Display):
+
+    def __init__(self, *args) -> None:
+        super().__init__(*args)
+        self.pad = self.newpad(self.rows, self.cols)
+
+    def update_logs(self, logs: Logs) -> None:
+        self.logs = logs
+
+    def display(self) -> None:
+        messages = self.logs.messages[-self.height:].reverse()
+        for i, y in enumerate(range(self.y + self.height - 1, self.y - 1, - 1)):
+            self.pad.addstr(y, self.x, messages[i][:self.width])