Fixes #218 Discount Coupon and Shipping Cost

Fix calculation for Fixed Coupons with Shipping Cost
Add some unit tests. This just covers off the use case for the bug,
but need to add a lot more tests for other Discount Coupon test cases.
oops. bad line break
Fixes #212 - additional autocomplete="off" for a few pages
Fixes #218 - Discount Coupon and Shipping Cost

I have made all the other tests a bit more robust.
Also fixed the edge case Linda addressed where a Fixed Coupon + Free Shipping where include_shipping = true
would show an incorrect coupon value, albeit order totals were correct.

Longer term, for the discount coupon tests, it would probably be better if the test inputs and expected results
were defined in a hash map(array) otherwise we could end up with hundreds of combinations addressed by individual tests
Merge pull request #222 from drbyte/autocomplete212

Fixes #212 - additional autocomplete="off" for a few pages
Merge pull request #221 from zcwilt/discount-coupons

Fixes #218 Discount Coupon and Shipping Cost
fmod_round is not managing values < 1
Add unit test
Remove redundant code
Fix Admin version
no message
Updated unit test
Merge pull request #226 from ajeh/shopping-cart-int-quantity

Remove redundant code
Merge pull request #225 from ajeh/fmod_round_issues

fmod_round is not managing values < 1
Merge pull request #101 from zencart/v160

zc 160