* examples: use test certs for running example-tls
* fixed a typo
* update usage printout for trustCertCollectionFilePath is not optional
* Revert "update usage printout for trustCertCollectionFilePath is not optional"
This reverts commit 2dd6d87f64.
* put back the usage of using system default CA and put notes for it
* fixed cmd-line argument options
* examples: make tls example easier to run
* Make the ca cert able to be verified by the server cert in openssl
* Make the port number consistent in each example (easy to copy paste wrong one)
* use correct netty-tcnative
* address comments