Merge pull request #8 from glynos/boost_string_ref

Boost string ref
Add ability to compile with clang without libc++.

To do so, supply -DCPP-NETLIB_DISABLE_LIBCXX=ON to cmake.
Merge pull request #9 from skystrife/master-integration

Add ability to compile with clang without libc++.
enabling cpp-netlib to be compiled into a single library

including uri
fix duplicate target definition
Merge pull request #10 from torbjoernk/make-one-cppnetlib-lib

enabling cpp-netlib (and uri) to be compiled into a single library
Encode/decode functions are now static members.
Assignment operator now takes another uri object by value.
Added a uri_syntax_error exception class.
Added a uri_builder_error exception class.
Added a new accessor that allows a client to specify the traits and allocator for a string.
encode/decode functions are now static members of uri.
Removed macro checks for deleted functions, default functions and noexcept.
Minor fixes to tests.
Updated stream operators.
Added a constructor to the uri class with a uri_builder argument.
Renamed 'relativize' to 'make_reference' and cleaned up the tests.
Updated the builder syntax.
base_uri was a dumb idea, I might put it back in later. Added tests to make sure the builder correctly encodes a path.
Added a few more tests to the URI builder.