More parse_options tests. Make --opt yes have value "yes" instead of "1". Change ok() to cmd_ok() in test-bash-functions. Mimic Perl modulue headers in Bash libs so update-modules will work with the latter.

util/test-bash-functions

@@ -128,9 +128,9 @@ is() {
    result $?
 }
 
-ok() {
+cmd_ok() {
    local test_command=$1
-   $test_command
+   eval $test_command
    result $?
 }