Few problems:
- we were passing a dict instead of a list of breakpoints
- if the breakpoint had a source which was {} we crashed
- we didn't support the 'removed' event
In Mojave, the TCL headers were removed, so we install brew tcl.
Oh and the all of the nonesense around authorizing applications to
connect a debugger mean the tests don't work, so we force LLDB to use
the system debugserver with LLDB_DEBUGSERVER_PATH.
