Memory leak fixes

• #48 fixes some more places where memory could leak; mainly involves clearing errors

Shout out to @astitt-ripple for their contribution.

Public key bit size, subject hash, and allocation changes

• #41 fixed a broken documentation link in the README, due to OpenSSL changing their directory structure
• #43 added a bitSize property for publicKey
• #45 added a subjectHash property with the output from X509_subject_name_hash(cert) in hexadecimal
• #46 fixed a memleak and changed the way the allocation occurs

Shout out to @pdspicer, @jkryl and @sonicdoe for their contributions.

Serial added

Thanks to a pull request by @ccstolley, the serial of the certificate has been added in.

Fix the Windows build.

Compliments of @asilvas, Windows compilation should now work.

A huge thanks to @asilvas for his pull request!

Compatibility with 0.11.3+ on OSX.

• Node 0.11.3 has a major change in v8::FunctionTemplate that breaks the current code with 0.11.3+ on OS X. Even though this branch of Node is still considered unstable, there is already a fix for OS X since it is obviously coming in 0.12.x. Linux doesn't seem to have the new v8::FunctionTemplate yet, for what reason I'm not quite sure of. In either case, there will be a fix available with this new code once it breaks on Linux. This has also not been tested on Windows or Unix yet, so it has been blocked on those platforms as well. Only OS X will use the newest code until there is a report about it breaking on Linux, Unix, or Windows.
• The build no longer depends on a Makefile, but instead handles everything in binding.gyp. This ensures compatibility with Windows without having to install MinGW for GCC or anything of that nature.
• Add more certificates for testing.
• General code clean up.

More clean up.

• Clean up Makefile
• Change some Handle types to Local types.
• Removed public_parse_cert in favor of parse_cert.
• .notBefore and .notAfter are now Date objects.
• Date checking example added to README.

Clean up and VERSION fix.

• Removed setupExports. This function was using during testing with G++ compilation to avoid repetition.
• Dynamic VERSION definition based on the version found in package.json. No need to set it manually in include/addon.h anymore.

Fix date parsing on Linux.

Fix date parsing throwing buffer overflow on Linux (#1).