Update Markdown with missing Perforce details.

Fix tabs/spaces in p4.rb
Merge merge lint changes
Fix lint errors
Merge pull request #192 from hunner/fix_lint

Fix lint errors
The helper calls host outside of an each loop
Merge pull request #193 from hunner/fix_helper

The helper calls host outside of an each loop
Merge pull request #187 from p4paul/master

Update Markdown with missing Perforce details.