command alias should respect bash posix

[franck-gaspoz]

command alias should respect bash posix

currently

alias {aliasName} {aliasText} 

Expected

alias {aliasExpression} 

with alias expression := aliasName = aliasText

issue

variables are substituted because they appears in a command parameter string ... it would be better if the substitution of variables is avoid in that case, thus the evaluation of parameters can be done when executing the alias text, otherwise the substitution is done twice (actual case)