Source data is now in toml format

The input text is now expected to be a toml file with a leading comment
section defining the battle map, according to the following rules:

1. Blank lines are ignored
2. Lines at the top of the file beginning with '#', optionally with
   leading spaces, is treated as map data
3. Map data continues until the first line not starting with a #.
4. Any subsequent lines are treated as metadata in toml format.
5. The metadata must contain the [map] section.
6. The [map] section must contain the "name" attribute.

The metadata is available as BattleMap.metadata; the map source is
available as BattleMap.map_string.

New convenience properties ahve been added to the BattleMap class for
accessing portions of the text-only output. This includes the header and
footer attributes.

test/test_mapper.py

@@ -16,18 +16,33 @@ def manager():
 def sample_map():
     return dedent(
         """
-        ........ 1
-        ........   ........ 2
-        ........   ........
-        .......L...D...  D
-        ........   .... ...
-        ........   ...d ...
-                      .
-            .........S. 3
-        5   .         .
-        ....S...   ...d.... 4
-        ........   ........
-        ........   ........
+        #    ........ 1
+        #    ........   ........ 2
+        #    ........   ........
+        #    .......L...D...  D
+        #    ........   .... ...
+        #    ........   ...d ...
+        #                  .
+        #        .........S. 3
+        #    5   .         .
+        #    ....S...   ...d.... 4
+        #    ........   ........
+        #    ........   ........
+
+        [map]
+        name = "sample map"
+        description = "sample dungeon"
+
+        [1]
+        name = "room 1"
+        [2]
+        name = "room 2"
+        [3]
+        name = "room 3"
+        [4]
+        name = "room 4"
+        [5]
+        name = "room 5"
 
     """
     )
@@ -39,23 +54,22 @@ def test_tileset_loader(manager):
 
 
 def test_renderer(manager, sample_map):
-    test_map = battlemap.BattleMap("test map", source=StringIO(sample_map), tileset=manager.load("ascii"))
+    test_map = battlemap.BattleMap(source=StringIO(sample_map), tileset=manager.load("ascii"))
     test_map.load()
     assert test_map.width == 21
     assert test_map.height == 12
-    assert test_map.source_data == sample_map.strip("\n")
 
     srclines = sample_map.splitlines()[1:]
     strlines = str(test_map).splitlines()
     for i in range(len(strlines)):
-        assert strlines[i] == srclines[i].ljust(21, " ")
+        assert strlines[i] == srclines[i].lstrip(' #').ljust(21, " ")
 
 
 def test_grid_coordiates(manager):
     coord_length = len(X_COORDS)
     map_size = 2 * coord_length + 1
-    bigmap = StringIO((("." * map_size) + "\n") * map_size)
-    test_map = battlemap.BattleMap("test map", source=bigmap, tileset=manager.load("ascii"))
+    bigmap = StringIO((' # ' + ("." * map_size) + "\n") * map_size)
+    test_map = battlemap.BattleMap(source=bigmap, tileset=manager.load("ascii"))
     test_map.load()
     assert test_map.grid.data[-1][-1].coordinates == (f"{map_size - 1}", X_COORDS[0] * 3)