Merge pull request #3545
1cbbeb6 gitian: Add openssl to linux deps (Wladimir J. van der Laan)
64be7f7 gitian: Build boost dependency for linux (Wladimir J. van der Laan)
7eb99a8 gitian: Reduce build time for boost windows dependency (Wladimir J. van der Laan)
714cdec build: Pass BOOST_CPPFLAGS to sleep implementation test (Wladimir J. van der Laan)
0d40f5a build: Allow providing extra libs for Boost Chrono (Wladimir J. van der Laan)
e4b991e build: Auto-detect whether -DBOOST_TEST_DYN_LINK is needed (Wladimir J. van der Laan)