Update README.md
added example query calls from multithreaded context
fixed connection pool init
changed pthread use to explicit join
Merge https://github.com/githubmonkey/libcql
Merge https://github.com/mstump/libcql
Added a comment to emphasize that the purpose of this demo extension is to highlight a potential bug inside libcql. As far as I know libcql is meant to be thread safe, but this demo
shows otherwise. A bunch of concurrent calls to pool->query() inevitably result in an exception "The associated promise has been destructed prior to the associated state becoming ready."

Hopefully, this will get the community interested in helping me debugging the demo and underlying libcql calls...
Make sure competing threads don't end up with the same stream id and overwrite each others callback functions.

This fixes a critical bug reported in https://github.com/mstump/libcql/issues/44
Remove comment that refers to a potential bug.

Also reduce runtime and thread number to something more reasonable. This was exaggerated to demonstrate the bug but the
problem has been addressed.
Merge https://github.com/githubmonkey/libcql