* Add client certificate support
allows WiFiClientSecureBearSSL users to use client certificate and private key for the WebSocker.
also added SSL functions for socket.io
```
java.lang.StackOverflowError
at java.util.regex.Pattern$Loop.match(Pattern.java:4785)
at java.util.regex.Pattern$GroupTail.match(Pattern.java:4717)
at java.util.regex.Pattern$BranchConn.match(Pattern.java:4568)
at java.util.regex.Pattern$CharProperty.match(Pattern.java:3777)
at java.util.regex.Pattern$Branch.match(Pattern.java:4604)
at java.util.regex.Pattern$GroupHead.match(Pattern.java:4658)
at java.util.regex.Pattern$Loop.match(Pattern.java:4785)
```