suggest: support other directory build
suggest: support other directory build

Use relative path from $(top_srcdir)/lib/ because $(top_srcdir)/lib/
is in include path.

myokoym/groonga,hiroyuki-sato/groonga,hiroyuki-sato/groonga,groonga/groonga,hiroyuki-sato/groonga,groonga/groonga,naoa/groonga,redfigure/groonga,hiroyuki-sato/groonga,redfigure/groonga,komainu8/groonga,groonga/groonga,hiroyuki-sato/groonga,cosmo0920/groonga,naoa/groonga,cosmo0920/groonga,hiroyuki-sato/groonga,groonga/groonga,kenhys/groonga,groonga/groonga,redfigure/groonga,kenhys/groonga,myokoym/groonga,komainu8/groonga,cosmo0920/groonga,myokoym/groonga,myokoym/groonga,kenhys/groonga,groonga/groonga,komainu8/groonga,cosmo0920/groonga,naoa/groonga,redfigure/groonga,komainu8/groonga,myokoym/groonga,groonga/groonga,naoa/groonga,hiroyuki-sato/groonga,cosmo0920/groonga,myokoym/groonga,myokoym/groonga,kenhys/groonga,kenhys/groonga,komainu8/groonga,komainu8/groonga,redfigure/groonga,cosmo0920/groonga,cosmo0920/groonga,groonga/groonga,redfigure/groonga,kenhys/groonga,komainu8/groonga,myokoym/groonga,kenhys/groonga,redfigure/groonga,naoa/groonga,naoa/groonga,kenhys/groonga,hiroyuki-sato/groonga,komainu8/groonga,cosmo0920/groonga,redfigure/groonga,naoa/groonga,naoa/groonga