docs typo [ci skip]
some additional checks to prevent encoding extensions that

do not have data in R509::CertificateAuthority::Signer
allow creation of privatekey with no params (2048-bit RSA)
modify R509::Cert#issuer and #subject to return R509::Subject objects

This requires changes to CRL::Administrator and
CertificateAuthoritySigner, but also lets us remove 4 unneeded methods
from the Cert object (since R509::Subject allows for elegant fetching of
subject components)
modify CRL::SignedList#issuer to return an R509::Subject too
refactor some of CertificateAuthority::Signer#sign and #selfsign to

break the methods down into more manageable sizes. still a bunch of work
to do to eventually allow refactoring of the spec tests but it's a
start.

Also fixed #selfsign so you can supply an array or an
R509::ASN1::GeneralNames object for san_names (just like you can with
the #sign method)
modifications to better support systems that do not have EC enabled

the tests for this are not very good at the moment (and missing on
privatekey). this will require some additional work
remove rcov task since 1.8 is no longer supported
modifications to only run the EC specific tests when EC is available
more ec compat work for non-ec rubies
updated readme to explain requirements/installation a bit better
add anyExtendedKeyUsage to the oidmapper batch register since older

OpenSSL installations don't have it by default
more spec modifications for non-ec supporting installs
drop the ec checks into a context block so we don't run the checks if

EC is unsupported.
add support for CRL entries with no revocation reason

added tests for no reason generation along with writing and reading CRL
lists with no reason
fix r509-parse to parse certs where there's no SAN extension
update version
expanded multi-policy test because i get nervous
modify engine support to use dynamic engine loading rather than old

static engine model
updated docs [ci skip]