ui: add diff.showfunc to tweakdefaults
This is a little risky, as I think we can have some encoding weirdness
crop up. showfunc also isn't the most robust feature, but it's still
often useful context...
Differential Revision: https://phab.mercurial-scm.org/D1610
--- a/mercurial/ui.py Wed Dec 06 16:42:24 2017 -0500
+++ b/mercurial/ui.py Wed Dec 06 16:43:07 2017 -0500
@@ -62,6 +62,7 @@
[diff]
git = 1
+showfunc = 1
"""
samplehgrcs = {