[tex-live] mactex installer overwrites excalibur dictionaries

[Sven de Vries]

Hi,

thank you for working and the 2018 update!

However, I noticed a small glitch (in my usage case):

I use the Excalibur spellchecker, that is installed in /Applications/TeX/ 
. However it stores its dictonaries along the binary (sadly).

Given that the mactexinstaller overwrites the /Applications/TeX-folder,
the user's dictionaries are gone thereafter. As a user, I will move my 
Excalibur-Folder directly into the applicationfolder.
For the installer, it would be nice of course, if it could move the 
dictionaries aside before overwriting them.

best
-sven