New dynamic type.

Class dynamic_t is designed to store json-like data. In the near future, it will replace Json::Value in the Cocaine.
Add rapidjson library to the source tree.

It will be used to parse config of the core.
Move the session into a separate compilation unit.
Kill JsonCpp with fire.

Whoa! It's really a big commit.
In Cocaine Core, JsonCpp was only used to read a config and Json::Value was used to store json-like data. But this library is big, it's slow, and it must be installed with the core. So i have removed it. Now cocaine::dynamic_t is used instead of Json::Value. RapidJson, which is fast header-only library, is used to parse a config.
Remove sources of JsonCpp.
Fix debianization.
Correct handling of integral values.

dynamic_t::as_int retuns value only if "this" stores dynamic_t::int_t and throws otherwise (for example, if "this" stores uint_t). So correct way to retrieve integral value from dynamic_t is using of method dynamic_t::to<YourIntegralType>.
Fix debianization, part 2.

Now dynamic_t is part of libcocaine-dev.
Avoid using of STL containers with incomplete types.

Now array_t and object_t are not stored in boost::variant directly. Instead unique_ptr's are stored.
Fix some compiler warnings.
Fix compiler warnings, part 2.
Avoid using of incomplete types with containers, part 2.

We must first define dynamic_t and only then object_t that is derived from std::map.
Move object_t into dynamic_t scope entirely.

Dynamic_t::object_t mustn't be synonym of detail::object_t. I can declare it directly in dynamic_t.
A little more correct comparison of dynamics.

Now it returns false when compares negative integer and unsigned integer.
Styling.
Fix assignment constructor.

Assignment constructor of dynamic_t must explicitly copy content from one incomplete_wrapper to another one (via assign_visitor).
Replace rapidjson sources with submodule.
Remove JsonCpp from cocaine-bf.spec.
Fix previous rebase.
Avoid tuples-in-tuples in generic streams.