README: improve Installation and Updating guides

[bobwya]

Responding to further user feedback... :-)

Updates to README:

• supply a simplified updater script (no comments / streamlined) that
  is easy to setup, for new users
• credit to @kenorb for suggesting the use of curl (replacing use of: wget)
• curl / install commands+options are available cross-platform on Linux / FreeBSD
• note: winetricks --self-update is not the same - this will only
  update to a newer release and will not update the bash.completion script

Fixes: #1192

Signed-off-by: Rob Walker bob.mt.wya@gmail.com

[qwertychouskie]

Honestly --self-update should update the whole thing, including the completions file. Also the --self-install proposed at #1194 (comment) would make this a lot simpler.

[austin987]

I agree with @qwertychouskie, I can't think of any reason why bash-completion shouldn't be updated, particularly since it would require no user effort and just a few lines of code.

@bobwya do you have strong reason for NOT updating bash-completion?

[bobwya]

@austin987 well my proposed changes do update the winetricks bash-completion script as well.

I've nothing against imrpoving the --self-update option or adding a --self-install. The instructions in the README are always going to have to include a manual download of winetricks (due to folks running obsolete versions) - so they aren't going to get much simpler... At least with the proposed changes - really just an iterative improvement - they will be simpler to follow.

[qwertychouskie]

@bobwya The idea with --self-install is that users just paste this command:

wget -qO - https://github.com/Winetricks/winetricks/raw/master/src/winetricks | pkexec sh /dev/stdin --self-install

That way there is no dependency on any installed version of Winetricks, or lack thereof.

[bobwya]

@qwertychouskie

Technically you've not invalidated my point (since your are manually downloading winetricks). But yes that is a nice one liner!