Rename iobj_DECLARE -> iobj_T
Rename log_channel_NROFCHANNEL->log_channel__NROF

Done also:

* Rename gcontext_api_NROFELEMENTS into gcontext_api__NROF
* Rename gcontext_api_NROFELEMENTS into gcontext_api__NROF
* Rename gconfig_NROFELEMENTS into gconfig__NROF
* Rename windowconfig_NROFELEMENTS into windowconfig__NROF
* Rename log_state_NROFSTATE into log_state__NROF
* Rename intop_NROFINTOPS into intop__NROF
* Rename termcol_NROFCOLOR into termcol__NROF
Remove field nextfree from syncqueue_t

Also:
* Functions nextfree_syncqueue & setnextfree_syncqueue removed
* Changed parameter order in insertfirst_queue and insertlast_queue
Rename unlink_linkd -> unlink0_linkd

Done also:
* Rename unlinkkeepself_linkd into unlinkself_linkd
* Rename spliceprev_linkd into splice_linkd
Decouple test of synccond_t from syncrunner_t

unittest_task_synccond uses knowledge about implementation
details of syncrunner_t to check its results.

Add functions to syncrunner_t to decouple the unittest
from syncrunner_t implementation details.