Better error handling on synchronous XML-RPC requests. Thanks to Erik Weiss for pointing this out to me!
A bit late on this, but updated the copyright year in a bunch of places.
Added support for custom headers

Added [XMLRPCRequest setValue:forHTTPHeaderField:] method which proxies
to the internal NSMutableURLRequest, useful to allow custom HTTP
headers.
Use default User-Agent

If no User Agent is set, pick the default one for the app. On iOS, it's
stored on NSUserDefaults as UserAgent, and it's what UIWebView uses.
Added Accept header to XMLRPCRequest

Some hosts using mod_security reject requests without an Accept header
Merge pull request #10 from koke/wordpress-ios

HTTP header improvements
Remove unnecessary build flags.
Stripping out the redundant copies of the license.
Time to get ready for the new year, plus some overdue housekeeping.
Avoid crashing if an element value is nil

If any of the values is malformed (e.g. a date set to "-0001113TT0::0::00") parseDate: would return nil, which is not allowed on arrays or dictionaries
Updated the script responsible for creating libXMLRPC.
support <nil> as struct member value

Although <nil> values are an XML-RPC extension it is widely supported.
This change allows for encoding <nil> values in structs by checking
dictionary values for an instance of NSNull.
optional XMLRPCConnectionDelegate method for upload progress

When sending RPC requests that contain large amounts of binary data
this delegate method allows for providing upload progress indicator.
performance improvement when encoding large binary data

The base64 encoder routine was taking upwards of 10-15 seconds to
encode a ~1 MB data buffer on iOS. This new routine by Matt Gallagher
is much much faster.
Merge pull request #15 from jiggak/master

<nil> values, upload progress indicator, and base64 performance improvement
Implement support for user specified xml encoders.

This is a combination of 10 commits.
Refactor XMLRPCEncoder to XMLRPCEncoderImpl.

This change renames XMLRPCEncoder to XMLRPCEncoderImpl to imply that
XMLRPCEncoder is actually an implentation of a interface yet to be defined. The
yet to be defined interface will allow users of the xmlrpc to prvide theier own
encoders to support XMLRPC extensions.

Create a protocol for XMLRPCEncoderImpl to implement.

This protocol will be used instead of XMLRPCEncoderImpl directly.

Have XMLRPC Request use the new XMLRPCEncoder protocol instead of XMLRPCEncoderImpl

Add a setEncoder method.

Remove header created by XCode

Refactor XMLRPCDencoderImpl to XMLRPCDefaultEndcoder

This refactor was made in response to a discussion on naming conventions here:
https://github.com/eczarny/xmlrpc/pull/17#r645514

Remove unnecessary prototypes from XMLRPCDefaultEncoder

The methods in defined in XMLRPCDefaultEncoder.h are already defined in the
XMLRPCEncoder protocol and there are are redundant.

Add a constuctor to initialize XMLRPCRequest with a given encoder.

HAve XMLRPCREquest take ownership of encoders assigned to it.

This commit causes XMLRPCRequest to retain all XMLRPCEncoders assigned to it.

Call default constructor when initailizing the default XMLRPC Encoder
Merge pull request #18 from Milyardo/xmlencoders-rc1

Implement support for user specified xml encoders.
Remove unused from XMLRPCEncoder protocol, fix memory leak in XMLRPCRequest
Merge pull request #19 from tomashanacek/master

remove unused method from XMLRPCEncoder protocol, fix memory leak in XMLRPCRequest
Ignore invalid/null dates