slug_count return errstr
test incomplete slug
slug parser
Merge branch 'master' into slugfix

Conflicts:
	tests/check_slug.c
update
Fix gvc graph
move slug related functions to slug.c and slug.h
improve r3_slug_parse function
fix autotools for check
wtf
asprintf returns memory pointer which is from malloc() not zmalloc()
Merge branch 'slugfix' of github.com:c9s/r3 into slugfix
contains_slug_char declare
const
fix prototype
fix warnings
check_json.c
inline static
install libjson-c
Add coverage option to gcc