Use text files for input and output rather than binary.

See:

  http://docs.python.org/3/glossary.html#term-universal-newlines
Allow text strings as input to commands.
Allow region selection to grab entire buffer if nothing is selected.
The 'region' parameter now takes a string value rather than a boolean.
If region is 'stdin', any selection is fed to the command as stdin.
Add an entry of 'Shell Command' into the Command Palette.
Merge branch 'feature/5-stdin' into develop

Fixes issue #5.
Bump version number.
Update changelog.
Merge branch 'release/0.8.0' into develop