updated ArangoDB download URL
Merge branch 'devel' into 2.1
update ArangoDB travis test version (2.1)
updated api version number (20100)
2.2 intitial checkin
added docs
added docs
make api compatible with 5.3
make api compatible with 5.3
make api compatible with 5.3
make api compatible with 5.3
make api compatible with 5.3
make api compatible with 5.3
make api compatible with 5.3
make api compatible with 5.3
make api compatible with 5.3
make api compatible with 5.3
fixed failing test
issue #174: fixed key validation
do not rely that much on error message