Log Message:
Update to 0.29.0

  mkc.configure.mk:
    - New variables MKC_CHECK_CC_OPTS and MKC_CHECK_CXX_OPTS were
      introduced for checking C/C++ compiler's options

  Makefile.inc and Makefile.common are included after system variables
  are set, in particular CC and CXX.

  CC_TYPE is now set in mk.init.mk

  Fixes for "err" and "warn" features.  Now verr(3), verrx(3),
  vwarn(3) and vwarnx(3) functions are detected correctly (the problem
  was seen on gcc-4.9/armv7).

  Fix support for COMPATLIB.  Objects for "features" should not be
  generated outside compatibility library.

  A number of fixes in regression tests: support for latest GCC,
  lib64 and lib/tri-ple-ts Linuxes.

  mkc_check_custom:
    - new option -e was introduced for checking stderr for emptyness
    - new option -b was introduced for printing yes/no instead of 1/0
    - additional options to compiler are passed via CARGS env. variable.