makefile: add $ to environment variables in help message

--HG--
branch : stable
templater: selecting a style with no templates does not crash (issue4140)

Running `hg log --style compact` (or any other style) raised a traceback when
no template directory was there. Now there is a message:

Abort: style 'compact' not found
(available styles: no templates found, try `hg debuginstall` for more info)


There is no test because this would require to rename the template directory.
But this would influence other tests running in parallel. And when the test
would be aborted the wrong named directory would remain, especially a problem
when running with -l.

--HG--
branch : stable
hgext: fix one typo in rebase

--HG--
branch : stable
extra : amend_source : 2690c995fcf379b22673d452f762fa53b43fdb1c