Ignore files related to Cocoapods.

These include Podfile, Podfile.lock, and Pods/.
Custom File.extname method which returns the filename if it is an extension
Remove .rb test
Sample files to test the new FileBlob.extension method
Merge conflicts from master fixed
Remove stylistic yet useless parentheses
Rename file for the test on non-existing extension
Use Rugged when computing Repository stats
Only cache strings, thanks
Mode must always be a String
Handle `nil` blob names
Missing file. Duh.
Proper incremental diffing
Fix travis build
DOCS
Fix the linguist binary
Bump 3.0.0b0
Use the new Rugged release
b1
Remove whitespace