[11909] Implement Pathfinder class to handle the actual pathfinding

Authors of this are Faramir118 and qsa.
Also thanks to many others for testing and suggestions!

src/game/MoveMapSharedDefines.h

@@ -25,4 +25,30 @@
 #define MMAP_MAGIC 0x4d4d4150   // 'MMAP'
 #define MMAP_VERSION 3
 
+struct MmapTileHeader
+{
+    uint32 mmapMagic;
+    uint32 dtVersion;
+    uint32 mmapVersion;
+    uint32 size;
+    bool usesLiquids : 1;
+
+    MmapTileHeader() : mmapMagic(MMAP_MAGIC), dtVersion(DT_NAVMESH_VERSION),
+                       mmapVersion(MMAP_VERSION), size(0), usesLiquids(true) {}
+};
+
+enum NavTerrain
+{
+    NAV_EMPTY   = 0x00,
+    NAV_GROUND  = 0x01,
+    NAV_MAGMA   = 0x02,
+    NAV_SLIME   = 0x04,
+    NAV_WATER   = 0x08,
+    NAV_UNUSED1 = 0x10,
+    NAV_UNUSED2 = 0x20,
+    NAV_UNUSED3 = 0x40,
+    NAV_UNUSED4 = 0x80
+    // we only have 8 bits
+};
+
 #endif  // _MOVE_MAP_SHARED_DEFINES_H