Added XML2SAXMetalinkProcessor class, which is a lot faster than
the predecessor, Xml2MetalinkParser class.
I tested them against 94KB metalink file with 1234 chunk
checksums.
The new one parsed it in 22msec, while it took 6000msec with old
one.
* src/XML2SAXMetalinkProcessor.{h, cc}
* test/XML2SAXMetalinkProcessorTest.cc
* src/MetalinkParserController.{h, cc}
* test/MetalinkParserControllerTest.cc
* src/MetalinkParserState.h: Also added 16 subclasses.
* src/main.cc
* src/Metalink2RequestGroup.cc
* src/MetalinkHelper.cc
* src/MetalinkEntry.cc
* src/ChunkChecksum.h
Rewritten Base64 class for better performance.
* src/Base64.{h, cc}
* test/Base64Test.cc
* src/HttpRequest.cc