Merge pull request #23 from zhaocai/master

 Make Client.escape_filename public
Add Vimrunner::Path and Vimrunner::Command for escaping.
Merge pull request #24 from AndrewRadev/command-and-path

Add Vimrunner::Path and Vimrunner::Command for escaping.
Slight improvement for old error handling
Add client.foreground to Bring the server to foreground
Ignore .orig file