v1.0rc3 Release Candidate

This is a bugfix release and a potential 1.0 candidate.
There is one extra feature included here - the facility to change the syslog identifier at run-time.

Changes from 1.0rc2

• Feature: allow changing the identifier for syslog (+tests)
• ipc: Set send and receive buffer sizes
• ipc: Set buffer size used by ipcs service
• ipc: Return -errno when getsockopt/setsockopt fails
• example: fix simplelog usage message
• log: defined value as an index-pointer after static slots
• log: convert log target defined values into enum values
• log: better (fixed) documentation for funcs returning "slot" index
• log: refactor static target slots state initialization
• log: convert few more instances to use enum qb_log_target_slot
• log: qblog.h unify descriptions before the code examples
• CI: Multiple fixes
• doc: Fix typos and reword several parts to be clearer
• build: misc spec file cleanups
• build: Add gcc pragmas for printf formats
• build: grab "dependent_headers" from respective Makefile.am
• build: header-based man pages: dependent_headers - blacklist
• build: header-based man pages: include also qbdefs.h+qbrb.h
• build: GCC < 4.6 does not support diagnostic push/pop pragmas
• build: fix man3 pages not installed