The new version of rustc 1.14.0-nightly (144af3e97 2016-10-02) has new
linting warnings/errors. This commit fixes them.
Signed-off-by: Salim Afiune <afiune@chef.io>
Added same alias funtionality for flags, now you can do:
```
Arg::with_name("flg")
.long("flag")
.short("f")
.alias("not_visible_flag")
.visible_alias("awesome_v_flag")
```
Signed-off-by: Salim Afiune <afiune@chef.io>
There are some cases where you need to have an argument to have an
alias, an example could be when you depricate one option in favor of
another one.
Now you are going to be able to alias arguments as follows:
```
Arg::with_name("opt")
.long("opt")
.short("o")
.takes_value(true)
.alias("invisible")
.visible_alias("visible")
```
Closes#669
