alias: improve help text for command aliases
Displays the line "alias for: hg ..." with the original command including options,
followed by the command's original help text.
#!/bin/sh
hg init
cat > a <<EOF
a
b
c
EOF
hg ci -Am adda
cat > a <<EOF
d
e
f
EOF
hg ci -m moda
hg diff --reverse -r0 -r1
cat >> a <<EOF
g
h
EOF
hg diff --reverse --nodates