With the  latest changes in the code base (dropping inline options / option
buttons in the Extension manager) for Thunderbird 60 the dialogs do not display
as expected: no Ok / Cancel buttons, no background / title bars, too largee
fonts and no background. 

There are also some problems with the styling of toolbar buttons and statusbar
buttons. The necessary code changes are summarized here:

https://wiki.mozilla.org/Thunderbird/Add-ons_Guide_57

in particular:

# for (x in fixIterator(obj)) (removed due to removal of __iterator__) --
replacement: for (x of fixIterator(obj))

# nsILocalFile -- replacement: nsIFile

# The bindings for the toolbar customization have moved from "global" to
"messenger" - changes in chrome.manifest:
style chrome://global/content/customizeToolbar.xul    chrome://.../skin/...
.css appversion<59.0a1
style chrome://messenger/content/customizeToolbar.xul chrome://.../skin/...
.css appversion>=59.0a1

# CSS for the preference dialogs has moved from Mozilla core to Thunderbird.
add <?xml-stylesheet type="text/css"
href="chrome://messenger/skin/preferences/preferences.css"?>

# The statusbarpanel-iconic and statusbarpanel-iconic-text was removed, use
toolbarbutton instead

Created an attachment (id=8394) [details]
3.5 prerelease 86

Tested with Thunderbird Daily 60.0a1 (2018-02-24) (32-bit)

Created an attachment (id=8433) [details]
3.10 prerelease 102

Added warnings about incompatible license if a license for a different Add-on
is entered  (licenses must start with QF)

bumped max version to 60.* to be ESR compatible

(From update of attachment 8394 [details])
marked this one obsolete - 60 beta requires strict compatibility. please
install 3.5 pre 102

(From update of attachment 8433 [details])
corrected title

Implemented Version 3.5 Released May 3, 2018