- syntax as per Bourne/Korn shell
      ${parameter:+altValue}

  If parameter is unset or null, nothing is substituted.
  Otherwise the \c altValue is substituted.

Removed test objs.

This reverts commit de564957.

Conflicts:

	applications/utilities/postProcessing/dataConversion/foamToTecplot360/tecio/examples/gridsolution/gridsolution.cpp

No "axis" required - when considering omegaDot the concept becomes meaningless.

Centre of rotation can be specified, to avoid it needing to be the origin, and
to allow it to move.

- syntax as per Bourne/Korn shell
      ${parameter:-defValue}

  If parameter is unset or null, the \c defValue is substituted.
  Otherwise, the value of parameter is substituted.

- eg,
       "$USER $(PWD) $USER"  ->  "username $(PWD) $USER"
  instead of
       "$USER $(PWD) $USER"  ->  "username $(PWD) username"

  this is noticable in some dynamicCode usages

STYLE: consolidate all string expand code into stringOps