Add elliptic curve key certificate support.

Includes

*curve method returning name of the curve
*move bit_length to XS (extracting the length for ec-certificates is more complicated). Should speed it up for the others too
*adjust modulus and pubkey to also return the ec-public key
*pubkey_type returns ec for ec-certs.
*testcase with thawte ec-cert
*compiles fine on systems where openssl is compiled without ec and fails gracefully.

All tests passed on the systems I had access to, which included systems both with and
without openssl ec-support.

The pubkey_type change also includes a crash fix of maugier which is required for systems
with openssl without ec support.
Merge pull request #21 from amannb/ec3

Add elliptic curve key certificate support.
Fix various Github issues.
Merge from HEAD.
repository cpan metadata added
typo fix
Merge pull request #27 from dsteinbrunner/patch-2

typo fix
Merge pull request #26 from dsteinbrunner/patch-1

repository cpan metadata added
Merge remote-tracking branch 'dsully/master'

Conflicts:
	X509.xs
	t/x509-ec.t