Mention 7 recent bug fixes and their associated contributors

Added 11 bugs and 7 contributors

The curl command line utility would display the the completed progress
bar with a percentage of zero as the progress routines didn't know the
size of the transfer.

Users using the Secure Transport (darwinssl) back-end can now use a
certificate and private key to authenticate with a site using TLS. Because
Apple's security system is based around the keychain and does not have any
non-public function to create a SecIdentityRef data structure from data
loaded outside of the Keychain, the certificate and private key have to be
loaded into the Keychain first (using the certtool command line tool or
the Security framework's C API) before we can find it and use it.

Since we're adding new stuff, the next release will bump the minor
version and we're looking forward to 7.31.0

... in order to prevent an artificial timeout event based on stale
speed-check data from a previous network transfer.  This commit fixes
a regression caused by 9dd85bce.

Bug: https://bugzilla.redhat.com/906031

Most notable the security advisory:
http://curl.haxx.se/docs/adv_20130412.html

added "tcpkeepalive on Mac OS X"

I noticed that aria2's SecureTransport code disables insecure ciphers such
as NULL, anonymous, IDEA, and weak-key ciphers used by SSLv3 and later.
That's a good idea, and now we do the same thing in order to prevent curl
from accessing a "secure" site that only negotiates insecure ciphersuites.

3 more bug fixes, 6 more contributors

More changes, bugfixes and contributors!

I found out that ECC doesn't work as of OS X 10.8.3, so those ciphers are
turned off until the next point release of OS X.

The flag can be used in pycurl-based applications where using the multi
interface would not be acceptable because of the performance lost caused
by implementing the select() loop in python.

Bug: http://curl.haxx.se/bug/view.cgi?id=1168
Downstream Bug: https://bugzilla.redhat.com/919127

8 more bugfixes, one change and a bunch of contributors

With all the recent imap changes it wasn't clear what new features and
fixes should be included in the release notes.

The option needs to be set on the SSL socket.  Setting it on the model
takes no effect.  Note that the non-blocking mode is still not enabled
for the handshake because the code is not yet ready for that.