Gwenhywfar

os: add support for thread conditional variables

- implemented for POSIX and Windows systems (latter not tested, yet)
- add system-dependent header files to allow for use of internal mutex
representation for use with pthread_cond_wait()/SleepConditionVariableCS()

msgio: added dbParsedInfo to GWEN_MSG

The endpoint code for a protocol needs to parse the data anyway (e.g.
the MQTT or the HTTP endpoint), so this parsed info can now be used by
apps as well removing the need to parse a message twice.

msgio: increased verbosity.

msgio: fixed a memory leak.

increased BUILD part of version.

msgio: added started apidoc, removed RUN virtual function.

Merge branch 'mp-202302-ipc3' containing msgio API.

msgio: renamed files, types and functions to no longer include "2".

Version 1 of the MSGIO api was soon replaced by version 2 which works much
better. However, this is still in my personal branch so we can declare that
version 1.

Revert "msgio: added timeOfLastIo."

This reverts commit 1f62477db820c44718c7be9b8f6f6cc1f18a42f2.

msgio: added timeOfLastIo.

msgio: removed first version of msgio api.

msgio: decreased verbosity.

msgio: fixed a bug.

Need to rewind pos pointer in added messages otherwise the handling code
things the message was completely handled already.

msgio: Increased verbosity.

msgio: added GWEN_Msg_GetMaxSize().

msgio: introduced callbacks around writing packets

The AqHome project's wire protocol uses a BUSY line to mark/detect whether
the bus is currently in use.

Before sending a packet over the wire the BUSY line needs to be checked
and if free pulled down to mark the bus as BUSY. After sending the packet...

msgio: sending and receiving messages works.

msgio: set default name if none given.

msgio: more work on modules, added test. connect/accept now basically works.

msgio: More work on rewriting of new msgio module.

- added some endpoints:
- ipc
- tcp client
- tcp service
- msg layer
- added function GWEN_Msg_AddBytes()

endpoint2_tcpc: added GWEN_TcpcEndpoint2_StartConnect().

Also some beautifications and increased verbosity.

endpointmgr: increased verbosity.

os/posix/inetsocket: added missing important ERRNO (EINPROGRESS).

This is needed to actually check for result of pending connect().

msgio: Started working on 2nd iteration of endpoint code.

Simplified code.

Fixed a typo which caused APOBANK to reject a HTTP request (thanks to Anselm!!!)