create USES=gem and update rubygem- ports to use it
Note that for now ports still have to have USE_RUBY=yes to use USES=gem
PR: 209041
Differential Revision: https://reviews.freebsd.org/D6070
Set NO_ARCH for remaining rubygem-* ports with no arch dependent files
Obtained from: DEVELOPER_MODE
With Hat: ruby@
Sponsored by: RideCharge Inc / Curb
misc/rubygem-mime-types117: rename to misc/rubygem-mime-types1
Update misc/rubygem-mime-types117 to the latest version that will work with
rails 3.x and rename to properly reflect the version.