Use NullSearchResults object in case sphinx raises "out of bounds"
Use NullSearchResults object in case sphinx raises "out of bounds"

When the requested page makes the calculated offset higher than sphinx's
max_matches it raises "offset out of bounds (offset=110490,
max_matches=1000)". This change handles this case by returning a
null-object instead.

rae/gitorious-mainline,spencerwp/mainline,gitorious/mainline,gitorious/mainline,tigefa4u/gitorious-mainline,elcom/gitorious,elcom/gitorious,Gitorious-backup/mainline,SamuelMoraesF/Gitorious,SamuelMoraesF/Gitorious,Gitorious-backup/mainline,SamuelMoraesF/Gitorious,spencerwp/mainline,rae/gitorious-mainline,elcom/gitorious,spencerwp/mainline,tigefa4u/gitorious-mainline,Gitorious-backup/mainline,gitorious/mainline,elcom/gitorious,rae/gitorious-mainline,rae/gitorious-mainline,spencerwp/mainline,gitorious/mainline,SamuelMoraesF/Gitorious,tigefa4u/gitorious-mainline,tigefa4u/gitorious-mainline,Gitorious-backup/mainline