- README: fix typo in 'sed' command line for minisat fix.
 - passes/cmds/select.cc, passes/fsm/fsm_recode.cc, passes/techmap/dfflibmap.cc: we need to #include <cerrno> for errno.
 - passes/cmds/select.cc, passes/fsm/fsm_recode.cc, passes/techmap/dfflibmap.cc: use c++-versions for includes.
 - passes/abc/abc.cc: #include <cerrno> for errno; use POSIX getcwd() for portability (get_current_dir_name() does not exist on BSD).
 - libs/ezsat/ezsat.cc: need to #include <cmath> or math.h for math functions.
 - kernel/log.h: add rusage()-based fallback for systems without clock_gettime().
 - kernel/driver.cc: need to #include <cerrno> or errno.h for errno.
 - kernel/register.cc: need to #include <cerrno> or errno.h for errno.
 - frontends/vhdl2verilog/vhdl2verilog.cc: #include <cerrno> for errno; use POSIX getcwd() for portability.
 - Makefile, kernel/posix_compatibility.h/.cc: provide POSIX.2008 fake implementation of open_memstream()/fmemopen() for pre-POSIX.2008 systems.
 - Makefile: OSX build rules (Apple's gcc and clang have no -rdynamic option and no librt).
 - Makefile: Generate debugger symbols and don't optimize for size in debug target (otherwise the debugger pretty hard to use).
 - Makefile: Reorder target concatenation in order to avoid use-before-built problems for source-include and linker dependencies.
 - Makefile: On OSX/macports, qmake-qt4 is named 'qmake' (the default Qt4 installation name, unless the distribution changes it).
 - Makefile: For OSX/Macports, we need to pass -I/opt/local/include and -L/opt/local/lib to give GNU libraries precedence over Apple's.
 - Makefile: Build a local minisat copy just like abc (to avoid dependency on broken/unmaintained distribution header files).
 - .gitignore: Ignore minisat directory.