Nice installer script

[tux314159]

There's a nice automated PKGBUILD if you're (like me) on Arch, but
I'm not sure about other distros. This installer script helps to automate stuff
on those other distros.

[valerio-bozzolan]

Hi thanks. Is this already proposed as pull request?

If yes, before merge I can propose to fix these problems found from https://www.shellcheck.net/

[Line 4:](javascript:setPosition(4, 8))
if [ ! $(whoami) = root ]; then
       ^-- [SC2046](https://www.shellcheck.net/wiki/SC2046) (warning): Quote this to prevent word splitting.
 
[Line 20:](javascript:setPosition(20, 4))
  (cd src; git clone $fwurl $fwname)
   ^-- [SC2164](https://www.shellcheck.net/wiki/SC2164) (warning): Use 'cd ... || exit' or 'cd ... || return' in case cd fails.

Did you mean: ([apply this](javascript:applyFixIndex([1])), apply [all SC2164](javascript:applyFixCode(2164)))
  (cd src || exit; git clone $fwurl $fwname)
 
[Line 21:](javascript:setPosition(21, 3))
  pushd ${srcdir}/${fwname} > /dev/null
  ^-- [SC2164](https://www.shellcheck.net/wiki/SC2164) (warning): Use 'pushd ... || exit' or 'pushd ... || return' in case pushd fails.

Did you mean: ([apply this](javascript:applyFixIndex([2])), apply [all SC2164](javascript:applyFixCode(2164)))
  pushd ${srcdir}/${fwname} > /dev/null || exit
 
[Line 25:](javascript:setPosition(25, 3))
  popd > /dev/null
  ^-- [SC2164](https://www.shellcheck.net/wiki/SC2164) (warning): Use 'popd ... || exit' or 'popd ... || return' in case popd fails.

Did you mean: ([apply this](javascript:applyFixIndex([3])), apply [all SC2164](javascript:applyFixCode(2164)))
  popd > /dev/null || exit