Note fixed build in UPDATES
Fix startup crash when libcrypto symbols are missing
Also detect missing symbols in libssl and libtcl
Show missing symbol errors in stderr on startup
Remove MAKEJOBS as it breaks job control
Regen after removing std_arg.h
Add CXX_FLAG_CHECK to detect compiler support for various flags
Only enable -fstack-protector if compiler supports it
Switch to using CXX_FLAG_CHECK for -fcolor-diagnostics [clang]
Merge branch 'maint'

* maint:
  Switch to using CXX_FLAG_CHECK for -fcolor-diagnostics [clang]
  Only enable -fstack-protector if compiler supports it
  Add CXX_FLAG_CHECK to detect compiler support for various flags
  Regen after removing std_arg.h
  Remove MAKEJOBS as it breaks job control
  Show missing symbol errors in stderr on startup
  Also detect missing symbols in libssl and libtcl
  Fix startup crash when libcrypto symbols are missing
  Note fixed build in UPDATES