Fixed test suite to work with Solaris Bourne shell:

Fixed test suite to work with Solaris Bourne shell:
1) Removed ! (negation) of statuses.
2) Removed initializations from export statements.
3) Replaced $() with ``.
4) Replaced $(()) (and expr) with new function arith_eval ().
(cherry picked from commit a6af3b6300e02ade9f223f8d91667f590d191dc9)