There was an issue when R=example@email.com went through link parsing
and the R= was considered to be part of the email address. Technically,
it is a valid email address, but with this change, we assume that
whenever a capital R= is in a linked text area, it indicates reviewers.
This is achieved by adding a zero width space after the '=' in the
change view prior to linkification. The linkify library correctly parses
the email without including R=.
Bug: Issue 5101
Change-Id: I1cca3b30e9cf503f2c2035768e7500bbc8081223
d63c519873