Parsing for emoticons, offered in Jira tickets

[cherub-i]

In issue descriptions, Jira parses certain strings as emoticons. Jira also offers to insert these emoticons through a function in the toolbar.
See https://confluence.atlassian.com/conf80/symbols-emojis-and-special-characters-1188407348.html / "Type the emoji keyboard shortcut".

These emoticons are translated into real emojis from Jira to MD representation.
Translation from MD back to Jira has also been done, but has not been tested.

These are all the emoticons in Jira-syntax:

:), :(, :P, :P, :D, ;), 
(y), (n), (on), (off), (!), 
(*), (*r), (*g), (*b), (*),
 (/), (x), (i), (+),  (-), 
(?), <3, </3
(flag), (flagoff)

The flag, flagoff are not supported by newer Jira editions, but are present in older ones.