Merge branch 'devel' of github.com:triAGENS/ArangoDB into 2.3
release version 2.3.0
Merge branch 'devel' of github.com:triAGENS/ArangoDB into 2.3

Conflicts:
	CHANGELOG
	Makefile.in
	configure
issue #1100: HAS() fails on doc[attribute_name]
fixed WITHIN_RECTANGLE for cluster
fixed tests
added tests
issue #1099: do not fail if general-graph.remove is used inside a transaction
added derived file
release version 2.3.0
issue #1103:  Error while importing user queries
Add missing `$(DESTDIR)` for `install-data-hook`

The target breaks on systems like Arch Linux, where package building is
done with `DESTDIR`, which is needed because the packaging step is not
allowed to modify files in the actual root system, instead it has to
work in a fakeroot environment.
added maxIterations param to GRAPH_EDGES and GRAPH_NEIGHBORS
issue #1104: edgeExamples broken or changed
removed unnecessary file
Changelog: fixed #1097.
Also respect required props in legacy schemas. Fixes #1097.
Swagger models should reflect required properties.
release version 2.3.0
fixed syslog