Bug#847099: yaml-cpp 0.5.2 is broken, please update to 0.5.3

[Younes Khoudli]

Package: libyaml-cpp-dev
Version: 0.5.2-4

Hi,
yaml-cpp 0.5.2 contains a major bug causing compilation errors when 
trying to remove a node.

(ie.
```
/usr/include/yaml-cpp/node/detail/impl.h:136:15: error: ‘equals’ was not 
declared in this scope
     if (equals(*it->first, key, pMemory)) {
```
)

This is fixed in yaml-cpp 0.5.3.

See https://github.com/jbeder/yaml-cpp/pull/303 for details.

Thanks,
Younes Khoudli