Support for endpoints with any number of arguments

Solution to https://github.com/landro/TesTcl/issues/9
In previous end state implementation, there was no support for commands without arguments (like reject, drop, discard) and with large number of arguments (like HTTP::respond with many headers).
There was possible to add many end states, but only last one was reported as successfull test execution.
Current implementation doesn't support multiple end states (last call to endstate replaces all previous calls) and has no limitation on number of arguments.

PS. Provided implementation passed all existing tests on current version of JTcl ;-)