Remove units from profile_period and history_period

Fix README to mention support of pg13+

Merge remote-tracking branch 'origin/PGPRO-8877'

Conflicts:
	compat.h

Caused by:
- 22212ba (PGPRO-8877)
  PostgreSQL 17 support.
- ed9f977 (master)
  Drop support for Postgres < 12

Release v1.1.5

PostgreSQL 16 support.

tagging pg-wait-sampling 1.1.4-2

Release v1.1.4

tagging pg-wait-sampling 1.1.4-1

tagging pg-wait-sampling 1.1.3-2

Release v1.1.3

* Fixed issue with collector detach from the shm_mq in the case of
ERROR/FATAL.
[PR#31](#31).

Release 1.1.2

* Add PostgreSQL 13 support (#24, thanks to @rjuju).
* Fixed wrong milliseconds calculation in the millisecs_diff() (#25,
thanks to @kasaharatt).