linux port, eclipse project + testapp

Here's the library port to Linux + gcc. I was unable to port tests yet, but app now works fine. There were some crashes when photo doesn't have geo information, so I had to put some parsing into try/catch block.
1. Strings are passed by const reference all over the library.
2. My opinion is that skipping parameter names in header file worsen maintainability, makes interface harder to understand at one glance
3. I think it's better for parameters not to have default values. See getFeed method, this was done one purpose. Let default values be only the part of public library interface, it's better not to spread these detail over all the implementation layers.