ReaderActivityIndicator: Oh god, my eyes, they buuuuurn.

Make this a real boy, with a transient lipc handle.
And get rid of the insane 1s sleep on affected ReaderView paints,
because ouchy.

This is completely deprecated anyway, so this is entirely pointless,
and mainly to prevent implementation details from creeping into
reader.lua.

frontend/apps/reader/modules/readeractivityindicator.lua

@@ -2,10 +2,8 @@
 local ReaderActivityIndicator = {}
 
 function ReaderActivityIndicator:isStub() return true end
-function ReaderActivityIndicator:init() end
 function ReaderActivityIndicator:onStartActivityIndicator() end
 function ReaderActivityIndicator:onStopActivityIndicator() end
-function ReaderActivityIndicator:coda() end
 
 -- Now, if we're on Kindle, and we haven't actually murdered Pillow, see what we can do...
 local Device = require("device")
@@ -31,7 +29,9 @@ local EventListener = require("ui/widget/eventlistener")
 local util = require("ffi/util")
 -- lipc
 
-ReaderActivityIndicator = EventListener:new{}
+ReaderActivityIndicator = EventListener:extend{
+    lipc_handle = nil,
+}
 
 function ReaderActivityIndicator:isStub() return false end
 
@@ -69,15 +69,15 @@ function ReaderActivityIndicator:onStopActivityIndicator()
                 "clientId":"com.github.koreader.activityindicator", \
                 "priority":true}}')
         self.indicator_started = false
-        util.usleep(1000000)
     end
     return true
 end
 
-function ReaderActivityIndicator:coda()
+function ReaderActivityIndicator:onCloseWidget()
     if self.lipc_handle then
         self.lipc_handle:close()
     end
+    self.lipc_handle = nil
 end
 
 return ReaderActivityIndicator