gcc5 5.1.0
gcc5 5.1.0

Update to latest stable release, reorder dependencies so withs and
withouts are together, add Leopard fixes, use `opt_share`,
use HTTPS mirror, add patch comment, remove a newline.

Closes #789.

Signed-off-by: Dominyk Tiller <53e438f55903875d07efdd98a8aaf887e7208dd3@gmail.com>

heuermh/homebrew-versions,coeligena/homebrew-verscustomized,jimhe/homebrew-versions,Ashton-W/homebrew-versions,UniqMartin/homebrew-versions,DomT4/homebrew-versions