prepare for 7.4.2 release
Added header in typedefs.h needed for building on ehel 5
Merge branch 'v7-stable-hidden' into v7-stable
doc: mention imported build patch for CENTOS5
Merge branch 'v7-stable'

Conflicts:
	ChangeLog
	configure.ac
	doc/manual.html
prepare for 7.5.2
doc: mention omelasticsearch bugfix in 7.5.2 changelog
doc: mention that omelasticsearch bug requires custom config to be triggered

This means the majority of users is not affected at all.
Merge branch 'v7-stable'
doc: mention that omelasticsearch bug requires custom config to be triggered
bugfix: very small memory leak in imrelp

more or less cosmetic, a single memory block was not freed, but this
only happens immediately before termination (when the OS automatically
frees all memory). Still an annoyance e.g. in valgrind.
minor code reduction
Merge branch 'v7-stable'
make use of new librelp generic error reporting facility

This leads to more error messages being passed to the user and
thus simplified troubleshooting.
librelp 1.2.0 is now required