Fix for #976 - Filestore links via browser

Fix for #976 - Filestore links via browser

+ GitLFS client support
+ FilestoreModel now parses meta file
+ Read meta heading from cache if available
+ Authentication based on accept headers for browser view filestore login
+ PathModel & PathChangeModel now understands filestore items
+ Zip & Rar downloads contain include filestore items
+ Filestore servlet returns LFS JSON error only if accepted by client
+ DiffStat now knows repository to allow identification of filestore items
+ Filestore items identified and returned via view, raw & blob links on
blame, commitDiff, commit and Tree pages