Revert "Merge pull request #28 from euromake/bug17"

This reverts commit 994bafaf70aae217aa6bd13147cd2362bb4abe89, reversing
changes made to d350372758a7eb6bd720e1d778d6f8293b842303.
17: grammar changed in IEEE 1003.1-2013
17: remove needless linebreak from case_item_ns
Merge pull request #30 from euromake/bug17

Align to Shell Grammar of IEEE 1003.1-2013