Render not found when failing to look for commit

1. Replace params key 'q' with 'extended_sha1'. A extended SHA1 syntax is explained in 'man gitrevisions'.
2. Change the placeholder of looking for commit.
3. Change the label of ref filter.

fix checkout tag name

Update to gitlab-shell 1.7.0 during 5.4-6.0 update

Remove the dependancy of grit from class Network::Graph