Allow specifying shell for running scriptlets
Some distributions insist on using bash specific commands in their
install scripts under the assumption that "sh" is a symlink to bash.
This can causes issues if (e.g.) their users what to change sh to
point at another shell, such as dash, that does not support these
features. Add a configure option to explicitly set the shell being
used to run install scripts.
Signed-off-by: Allan McRae <allan@archlinux.org>
Signed-off-by: Dan McGee <dan@archlinux.org>