detect Amazon Linux AMI, fix #1682
Merge branch 'master' of github.com:wayneeseguin/rvm
NEXT: update plan for 1.19.1
check only for active macports packages, cache the list, closes #1723
safer check of available packages for macports
fix running amazon requirements, update #1682
NEXT: update 1.19.1 with 1682
debian/ubuntu multiarch dependency checking.  fixes #1726
avoid output
Merge pull request #1727 from theschoolmaster/debian-ubuntu-multiarch-support

debian/ubuntu multiarch dependency checking
Clean up comments.

There is really only need to explain multi-arch.
NEXT: 1.19.1 plan 1727, change 1723 to 1725
do not fail in update-system when in read modes, update #1724
NEXT: update 1.19.1 with 1724
improve autolibs error, fix detecting errors, closes #1724, update #1720
NEXT: 1.19.1 update 1724
patch lives within the base system on FreeBSD, no point in checking for its presence.
Merge pull request #1733 from jasiek/master

Checking for the existence of patch via a package manager is not necessary
NEXT: 1.19.1 with 1733
do not try port for smf osx requirements, fix #1736