Remove some generated files from the dist.
Fix nested autoconf test for C++11 lambda support.
Rearrange order of C++11 class declarations to satisfy clang++.

clang++ complained of incomplete types, so foreward declarations were
not enough despite the code compiling with g++ 4.7.  Had to move
Address and Message to before Server.
Fix declaration of ServerThread::_add_method() virtual function.
Bundle::get_bundle() does not take an unused "path" parameter.
Add lo_bundle_get_timestamp() function.
Don't include lo_cpp.h by default since it could break older C++ code.
Merge branch 'master' into cpp
Add lo::Bundle::timestamp().