Reversing decision to use >\> and %\> as the escapes now for >> and %>.
Simply allowing >>> is the best, such as <<Hi <name>>>.
It will strip off the >> and leave > as the appropriate end of expression.
Added testTripleAngleOnEnds.  Even <<<x>>> works now.  There is no escape
for %>.  An update / Fixes antlr/stringtemplate4#17.
* Tweaked escapes so that \> becomes > in <<...>>. Do NOT replace if it's <\\>.
  a(x) ::= <<\>>>> yields >> as output.
  a(x) ::= <<>\>>> yields >> as output.

* Added warning about: "Missing newline after newline escape <\\>"
%\> is the escape to avoid end of string
no more >>> allowed on end of <<...>>

* Tweaked escapes in <<...>>. Do NOT replace if it's <\\>.
  Escapes: >\> means >> inside of <<...>>.
  Escapes: \>> means >> inside of <<...>> unless at end like <<...\>>>>.
  In that case, use <%..>>%> instead.
Updated documentation
Do not respond to recursive events caused by UI updates
STViz highlights template substring responsible for actual output text
Show user-instanced templates in bold in the STViz templates tree
Reference latest V3 runtime for bug fix
Show hidden (inherited+aliased) attributes grayed out in STViz
Fix glitches in STViz highlighter updates
Update CHANGES.txt