o Add '!' correctly when expanding Aliases.

o Add '!' correctly when expanding Aliases.
o Add shortcut macros for append() to make things more readable.
o The separator in append() is now a string instead of a char.
o In append(), only prepend the separator if the last char is not a '!'.
  This is a hack but it greatly simplifies '!' handling.
o In -l mode, Runas lists and NOPASSWD/PASSWD tags are now inherited
  across entries in a list (matches current behavior).
o Fix formatting in -l mode such that items in a list are separated by
  a space.  Greatlt improves readability.
o Space for name field in struct aliasinfo is now allocated dyanically
  instead of using a (big) buffer.
o In add_alias(), only search the list once (lsearch instead of lfind + lsearch)