tests for the use of '__name' metafield in 'tostring'

few extra tests for large numbers in 'tonumber'

new tests for 'string.format("%s")' with embedded zeros

added tests for minint < NaN (bug in 5.3.1 rc1)

can avoid domain error only in portable (_port) mode

testing message contents when testing errors

avoid too much dependence on string<->number coercions

extra test for 'table.remove' with index 0

bug (in the test): collector was not restarted in restricted mode

try to use only double quotes in shell commands