This commit removes "check_stderr" setting from itest! macro used
to generate integration tests. Without this setting on tests discarded
output of stderr making it very hard to debug the problem in test.
Numerous tests were changed by adding "--quiet" flag to not display
"Compile"/"Download" prompts.
After splitting "failFast" and "exitOnFail" arguments, there was a situation where failing tests did not exit with code 1.
* fixed argument value passed to Deno.runTests() in deno test
* fixed argument value passed to Deno.runTests() in std/testing/runner.ts
* added integration tests for deno test to ensure failFast and exitOnFail work as expected
* don't write test file to file system, but keep it in memory