add getEntries() to the CommandHistory API

so we can export them to lua
also bump the default history size to 5000 from the paltry 100 we had

library/include/Console.h

@@ -32,6 +32,7 @@ distribution.
 #include <assert.h>
 #include <iostream>
 #include <string>
+#include <vector>
 namespace tthread
 {
     class mutex;
@@ -114,6 +115,12 @@ namespace  DFHack
         {
             history.pop_front();
         }
+        /// adds the current list of entries to the given vector
+        void getEntries(std::vector<std::string> &entries)
+        {
+            for (auto &entry : history)
+                entries.push_back(entry);
+        }
     private:
         std::size_t capacity;
         std::deque <std::string> history;