Further help improvements:
Show command aliases in 'hg help something', unless in quiet mode.
Show short command description with 'hg help -q something'.
Show global options in verbose mode of command help.
State that Mercurial is a Distributed SCM.
+ hg clone a b
abort: repository a/.hg not found!
255
+ hg clone http://127.0.0.1:3121/a b
requesting all changes
abort: error: Connection refused
255
+ hg clone a b
abort: repository a/.hg not found!
255
+ hg init
+ hg clone . ../a
abort: destination '../a' already exists
1
+ hg clone a b
abort: repository a/.hg not found!
255
+ hg init
+ hg clone q
abort: destination 'q' already exists