update r509-ca-http to use the profile enforcer class from r509 0.10
update gemspec and version
support new crl changes from r509 0.10
compatibility with latest r509 HEAD (0.10 WIP) + more

* README updates
* Removed some 1.8.7 compatible stuff we don't need any more (1.9.3+ only)
deprecate crl get, fix specs, update README, update r509 version dep
update travis.yml to test against more relevant ruby versions
reorganize gemfile
add rbx required gems for r509
more for rubinius
Merge pull request #22 from reaperhulk/master

Merge changes to support r509 0.10