Use the latest libotr release
Set default Instantbird preferences with enhanced security settings
Ensure SSL/TLS is used by default for Facebook, IRC, and XMPP accounts
Update the config file to reflect addition of new patches
Fix typo in preferences.patch
Redesign the account creation protocol screen (closes #13323)
instantbird/build: apply all *.patch files

Apply all patches in the current directory, instead of listing them all
in the build script. They still need to be listed in the config file.

Change suggested by Sukhbir.
Include libstdc++.so.6 in tor-messenger tarball

We need to include libstdc++.so.6 from the compiler we used to compile
instantbird.

We will probably need a script similar to start-tor-browser to set
LD_LIBRARY_PATH before starting instandbird.
Compress tor-messenger tarball with xz to save space