NFD

This bug applies to ndn-cxx, NFD, and I guess everything else that uses boost (at least regular expressions library).

I'm not familiar with this register business, but I have seen this before.

In file included from ../tools/nfdc.cpp:31:
In file included from /usr/local/include/boost/algorithm/string/regex_find_format.hpp:15:
In file included from /usr/local/include/boost/regex.hpp:31:
In file included from /usr/local/include/boost/regex/v4/regex.hpp:48:
/usr/local/include/boost/regex/v4/regex_raw_buffer.hpp:132:7: error: 'register' storage class specifier is deprecated [-Werror,-Wdeprecated-register]
      register pointer result = end;
      ^~~~~~~~~
1 error generated.

Proposed fix is to suppress deprecated-register warning completely.