Merge pull request #1 from devinc/master

corrected old grsecurity setting detection
Update installer.sh

Add support for both stable_rss and stable2_rss feeds
Update installer.sh

Added gcc-plugin-dev as requirement and fixed architecture naming error when installing the build package
switch to xz archives
add xz-utils as dependency in description
Merge pull request #1 from rickard2/master

merge upstream changes