Fix various minor errors after the lua 5.2 conversion

Signed-off-by: Uli Schlachter <psychon@znc.in>

lib/awful/mouse/finder.lua.in

@@ -5,9 +5,9 @@
 -------------------------------------------------------------------------
 
 local mouse = mouse
-local wibox = wibox
 local screen = screen
 local timer = timer
+local wibox = require("wibox")
 local a_placement = require("awful.placement")
 local a_wibox = require("awful.wibox")
 local beautiful = require("beautiful")

lib/awful/tooltip.lua.in

@@ -5,9 +5,9 @@
 -------------------------------------------------------------------------
 
 local mouse = mouse
-local wibox = wibox
 local screen = screen
 local timer = timer
+local wibox = require("wibox")
 local a_placement = require("awful.placement")
 local beautiful = require("beautiful")
 local textbox = require("wibox.widget.textbox")

lib/awful/widget/graph.lua.in

@@ -253,7 +253,7 @@ function graph.new(args)
     _graph.fit = graph.fit
 
     for _, prop in ipairs(properties) do
-        _graph["set_" .. prop] = _M["set_" .. prop]
+        _graph["set_" .. prop] = graph["set_" .. prop]
     end
 
     return _graph

lib/wibox/layout/align.lua.in

@@ -22,7 +22,7 @@ local function draw(dir, layout, wibox, cr, width, height)
     local size_limit = dir == "y" and height or width
 
     if layout.first then
-        local w, h = width, height
+        local w, h, _ = width, height, nil
         if dir == "y" then
             _, h = layout.first:fit(w, h)
             size_first = h
@@ -34,7 +34,7 @@ local function draw(dir, layout, wibox, cr, width, height)
     end
 
     if layout.third and size_first < size_limit then
-        local w, h, x, y
+        local w, h, x, y, _
         if dir == "y" then
             w, h = width, height - size_first
             _, h = layout.third:fit(w, h)

lib/wibox/layout/fixed.lua.in

@@ -25,7 +25,7 @@ function fixed.draw_fixed(dir, widgets, fill_space, wibox, cr, width, height)
     local pos = 0
 
     for k, v in pairs(widgets) do
-        local x, y, w, h
+        local x, y, w, h, _
         local in_dir
         if dir == "y" then
             x, y = 0, pos