UI Refactor T41640

Make the UI API more consistent and reduce confusion with some naming.

mainly:
- API function calls
- enum values

some internal static functions have been left for now

source/blender/editors/space_graph/graph_draw.c

@@ -1109,7 +1109,7 @@ void graph_draw_channel_names(bContext *C, bAnimContext *ac, ARegion *ar)
 		}
 	}
 	{   /* second pass: widgets */
-		uiBlock *block = uiBeginBlock(C, ar, __func__, UI_EMBOSS);
+		uiBlock *block = UI_block_begin(C, ar, __func__, UI_EMBOSS);
 		size_t channel_index = 0;
 		
 		y = (float)ACHANNEL_FIRST;
@@ -1135,8 +1135,8 @@ void graph_draw_channel_names(bContext *C, bAnimContext *ac, ARegion *ar)
 			channel_index++;
 		}
 		
-		uiEndBlock(C, block);
-		uiDrawBlock(C, block);
+		UI_block_end(C, block);
+		UI_block_draw(C, block);
 		
 		glDisable(GL_BLEND);
 	}