Do a (superficial) port to c++ of some of the c sources. Update deps. Fix a few compiler warnings.
- Move the lib/query/ stuff up a level into lib/ - Associate directly with the Query object - Rework the Query object to be C++ rather than mixed with C - Update all dependencies, tests
Split off the parsing/handling code from the mu command server into mu-server, and only leave the external interface (the mu4e repl) in mu-cmd-server.
