Revert "abc.sh: edit _tarFLAGS to detect compression"

The -a option does not work on FreeBSD.

This reverts commit b79b5025495a1b0c2259ac7888ac96b922aab3da.
version bump 0.1.3 > 0.1.4
abc.sh: enable _tar_FLAGS to be set automatically

Script now uses case statement to determine tar flags, rather than -a option
which was not FreeBSD compatible.