misc sftp changes

Modified sftp task to only use a single sftp session and to use actual Error objects instead of strings for errors.
update grunt
Merge branch 'patch-1' of github.com:mscdex/grunt-ssh into mscdex-patch-1

# By Brian White
# Via Brian White
* 'patch-1' of github.com:mscdex/grunt-ssh:
  misc sftp changes
Merge branch 'mscdex-patch-1'

# By Brian White
# Via Andrew Jones (1) and Brian White (1)
* mscdex-patch-1:
  misc sftp changes
update changelog and version
tidy
tidy
Merge branch 'junglebarry-master'

* junglebarry-master:
  tidy
merge #64