Guard PIConnection, thread primitives, PICodeParser and other feature
code behind PIP_HAS_THREADS/PIP_HAS_FILESYSTEM. In CMake generate the
feature flags summary from the single PIP_HAS_FLAGS list (used by the
add_definitions loop as well), default ICU to OFF and make introspection
also require PIP_HAS_SOCKET. Build system/thread test suites only when
the corresponding feature flags are enabled.
* PIThread::~PIThread() now unregister itself from introspection, if terminates than show warning
* PISystemMonitor now correctly stops
* PIPeer now can correctly stopAndWait
* PIPeer::destroy(), protected method for close all eths and threads
* new PIINTROSPECTION_STOP macro
* Introspection now can be correctly stopped by macro, more safety
ClientServer:
* ClientBase::close() stop and disconnect channel
* Server clients clean-up now event-based
* No warnings on client destructor