Compilation fails on clang 3.4.1 (and presumably later, tho I haven't tested) with
```
src/reader.cpp:131:59: error: no viable conversion from 'iterator' (aka '__map_iterator<typename __base::iterator>') to 'std::map<std::string, unsigned int>::const_iterator' (aka '__map_const_iterator<typename __base::const_iterator>')
std::map<std::string, unsigned int>::const_iterator it = counterMap.find("text/html");
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/include/c++/v1/map:713:29: note: candidate constructor (the implicit copy constructor) not viable: no known conversion from 'iterator' (aka '__map_iterator<typename __base::iterator>') to 'const std::__1::__map_const_iterator<std::__1::__tree_const_iterator<std::__1::__value_type<std::__1::basic_string<char>, unsigned int>, std::__1::__tree_node<std::__1::__value_type<std::__1::basic_string<char>, unsigned int>, void *> *, long> > &' for 1st argument
class _LIBCPP_TYPE_VIS_ONLY __map_const_iterator
^
```
because we are not using the right type for the map iterator. As we are using
C++11, let's use `auto` and make compiler set the right type for us.
There is no more integrated build of dependencies in the build system.
Dependencies are discovered using pkg-config except for ctpp2 where there
is no pkg-config file.
