Plans: Make it possible to give plans a name.

(cherry picked from commit d9b553f130a6eda36e2eea217785f829d3d8624e)

src/saveload/extended_ver_sl.cpp

@@ -45,7 +45,7 @@ std::vector<uint32> _sl_xv_discardable_chunk_ids;           ///< list of chunks
 static const uint32 _sl_xv_slxi_chunk_version = 0;          ///< current version os SLXI chunk
 
 const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
-	{ XSLFI_ENH_VIEWPORT_PLANS,     XSCF_IGNORABLE_ALL,       2,   2, "enh_viewport_plans",        NULL, NULL, "PLAN"      },
+	{ XSLFI_ENH_VIEWPORT_PLANS,     XSCF_IGNORABLE_ALL,       3,   3, "enh_viewport_plans",        NULL, NULL, "PLAN"      },
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, NULL, NULL, NULL, NULL },// This is the end marker
 };
 

src/saveload/plans_sl.cpp

@@ -21,6 +21,7 @@ static const SaveLoad _plan_desc[] = {
 	SLE_VAR(Plan, visible,        SLE_BOOL),
 	SLE_VAR(Plan, visible_by_all, SLE_BOOL),
 	SLE_VAR(Plan, creation_date,  SLE_INT32),
+	SLE_CONDSTDSTR_X(Plan, name, 0, 0, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_ENH_VIEWPORT_PLANS, 3)),
 	SLE_END()
 };