Build fails with CPP0X enabled. #46

I just attempted to build the library with cpp0x support enabled and I encountered build errors. I have tracked down the issues and have outlined them below.

First, in src/httpserver/webserver.hpp, in the #include section, <set> is conditionally included if CPP0X support is not enabled (https://github.com/etr/libhttpserver/blob/master/src/httpserver/webserver.hpp#L36-40). This causes errors because std::set is used elsewhere throughout the code. This can be fixed by changing:

#ifdef USE_CPP_ZEROX
#include <unordered_set>
#else 
#include <set>
#endif 

to

#ifdef USE_CPP_ZEROX
#include <unordered_set>
#endif 
#include <set>

Next, when declaring the bans and allowances variables on https://github.com/etr/libhttpserver/blob/master/src/httpserver/webserver.hpp#L238-244, std::unordered_set is used if CPP0X support is enabled, but the type that it stores (http::ip_representation) does not have std::hash defined for it. In my opinion, unordered set may not be required here as O(lg n) lookup is probably sufficient for the purposes that it serves, and the time gain that you would get with O(1) lookup with unordered set likely doesn't outweigh the space overhead.

Next, in src/webserver.cpp, there are quite a few instances where std::make_pair is called but the template arguments are provided; they should always be omitted with make_pair, and because C++0x is stricter with type conversions, they fail to compile. The offending lines are https://github.com/etr/libhttpserver/blob/master/src/webserver.cpp#L252, https://github.com/etr/libhttpserver/blob/master/src/webserver.cpp#L1417, and https://github.com/etr/libhttpserver/blob/master/src/webserver.cpp#L1428.

Lastly, for some reason, when running configure with CPP0X enabled, the --std=c++0x flag is missing from somewhere in the generated Makefile. To fix this I had to run the configure command as follows:

CXXFLAGS=--std=c++11 ../libhttpserver/configure --prefix=/usr --enable-cpp0x

I have no clue how the configure script works so I don't know what would have to be modified to make this work out of the box.