Moved off the logic inside the function 'sp64inInjectTag(...)' into a new function 'sp64inInjectTagForEmail(...)'.  Deprecated the original function.
No need to use double-quotes here.
Renamed the variable '$strDataSp' to '$strAttrDataSp'.
Storing the value of the 'href' attribute in a local variable '$strAttrHref'.
Moved the logic that determines the value of the attribute 'data-sp64in' up above the rendering logic.
Moved the declaration of the '$strURLPath' variable closer to where it is being used.
Minor description detail.
Rendering HTML attribute "data-sp64in-nogd='true'" when GD is not available.
Processing the 'data-sp64in-nogd' attribute on the client.
No longer sending 'nogd' as value in the 'data-sp64in' attribute.
Moving the existent email check up to the top of the event handler function.
Consolidated 2 php lines into 1.
Consolidated 2 more php lines into 1.
Added parent <span>.
Configuring the default CSS class for the parent <span> to be 'sp64in_parent'.
Enclosed the configuration variables inside the object 'sp64in_cfg'.
Calling 'sp64inInjectTagForEmail(...)' rather than the deprecated function 'sp64inInjectTag(...)'.