Thread API wrappers required for thread logging

[ethouris]

Depends: #1049

This applies part of the thread logging, which comprises thread API wrappers. This includes:

• type aliases (currently just aliases) for pthread_mutex_t and phread_cond_t
• functions operating on them for locking/unlocking and creation/destruction
• shorthand functions for the threads:
  • jointhread: refers to pthread_join
  • isthread: checks if the thread id value is equal (taken as a good deal that thread isn't running)

Not provided wrappers for pthread_create and pthread_t. Possible wrappers for them should be more high level and therefore were not created. They should involve a wrapper over a handler function so that the possible thread logging on a new started thread or exited thread comes from the elevated handler.

This is the part that is only required for thread logging.

[maxsharabayko]

@ethouris This PR is already outdated and can be closed, right?

[ethouris]

It's long not updated, but the update is impossible until your fixes for timers are merged - in particular, the one that eliminates the type definition difference for monotonic condition variable.