Conflict between base64 in twitcurl and libcurl

```
What steps will reproduce the problem?
1. build twitterClient
2.
3.

What is the expected output? What do you see instead?
expected clean build but got unresolved external symbol errors for
Curl_base64_encode and Curl_base64_decode

What version of the product are you using? On what operating system?
got twitterClient and libtwitcurl using SVN (latest); building against
curl-7.34.0 using VC++2010 on Windows 7

Please provide any additional information below.
both libraries have modules called base64; presumably because of the linking
order the twitcurl module is overriding the libcurl module; both modules define
similar functions but with different names so the linker cannot find the
functions referenced by libcurl functions

```

Original issue reported on code.google.com by `raymondg...@gmail.com` on 24 Dec 2013 at 7:09