remove the gpg stuff from hgeditor (superseded by the signing extension) remove the gpg stuff from hgeditor, update the comments to make it clear it can be used to show a diff while commiting

diff -r 3903775176ed b
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+123
diff -r 3903775176ed b
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+123