Remote backend doesn't use C code

So there's no use in setting bot CFLAGS and CXXFLAGS
Disabling optimization has no effect

Our default CXXFLAGS set in configure.ac
override those settings.
Don't set BOOST_CPPFLAGS and THREADFLAGS twice

They are already set in AM_CPPFLAGS
Remove duplicate include paths

They're already specified in AM_CPPFLAGS
Remove duplicate POLARSSL_CFLAGS
Movve LIBZMQ_CFLAGS to AM_CPPFLAGS
Set preprocessor flag, not compiler
Link library with zeromq

The test binaries link with the library
Link library with polarssl

The test binaries link with the library
Conditionalize linking with zeromq
Split flags and libraries
Reorder
Move BOOST_UNIT_TEST_FRAMEWORK_LDFLAGS to library
Remove commented out code
Add our own include paths first
Check for headers relative to top_srcdir
Don't look for pdns headers in system includes
Order headers
Whitespace
Link library with -ldl, not binaries

The library is the one doing the dlopen