Address two Samson security concerns

See JIRA items Samson-13 and Samson-14
Update tests due to use of shellescape
Remove unwanted added whitespace
Refactor code generating shell commands

I removed sanitize() and replaced it with h().  Use of quotes also
removed in a couple of areas; let shellescape do its job.  It is now
possible to have a name with an embedded apostrophe; no additional code
required for this.
Merge pull request #58 from zendesk/pobrien/sec_fixes_1

Security Fixes for XSS and Shell Injection