New version of Debugging Toolkit

I've released version 1.3 of the Debugging Toolkit , which makes Debug.pp compatible with LR 4 beta. Please let me know of any issues. If anyone other than Rob uses this, drop me a note so I have some sense of usage.

It uses the following function to determine whether a value is an SDK object (e.g. LrFolder):

--[[----------------------------------------------------------------------------
private boolean
isSDKObject (x)

Returns true if "x" is an object implemented by the LR SDK. In LR 3, those
objects are tables with a string for a metatable, but in LR 4 beta,
getmetatable() raises an error for such objects. 
------------------------------------------------------------------------------]]

local majorVersion = LrApplication.versionTable ().major

local function isSDKObject (x)
    if type (x) ~= "table" then
        return false
    elseif majorVersion < 4 then
        return type (getmetatable (x)) == "string"
    else
        local success, value = pcall (getmetatable, x)
        return not success or type (value) == "string"
        end
    end