call HEAD when file delete and file exists timestamp is the same
call HEAD if file exists and is deleted with same timestamp
further updates to HEAD on delete/existing on same timestamp
additions to inject_error
harden calls to strncat
inject error and unit test additions for HEAD/timestamp work
free existing
restricting scope of variable per cppcheck
Merge pull request #135 from pantheon-systems/head-on-equal-timestamps

When propfind finds that file was existing and also deleted on the same timestamp, call HEAD to see if file exists on server