Refactor reading from stdin so --type option works

[simeonwillbanks]

When reading from stdin, a filename must be set with an extension since the GitHub gist API infers file type from filename and not extension. Thanks to @ottomata for the original implementation. Fixes Issue #101.

[simeonwillbanks]

Testing

$curl -s https://raw.github.com/LessonPlanet/gist/issue-101-type-option-not-working-from-stdin/gist > gist && chmod 755 gist && mv gist /usr/local/bin/gist

$mvim /usr/local/bin/gist # Edit file to include 09a79f8

$exec $SHELL

$cat test.rb | gist -trb -d'Testing 09a79f8dc3'
https://gist.github.com/3183191

[simeonwillbanks]

Testing Again

$ gst

On branch issue-101-type-option-not-working-from-stdin

$ rake standalone

$ mv gist /usr/local/bin && chmod 755 /usr/local/bin/gist

$ diff /usr/local/bin/gist gist
1203,1212c1203
< # NOTE github gist API doesn't seem to
< # pay any attention to :extension here.
< # Since we don't have a read filename,
< # create one based on timestamp and extension.
< # Automatic syntax highlighting must be inferred
< files = [{
< :input => input,
< :extension => gist_extension,
< :filename => Time.now.utc.to_s.gsub(/\W/, '') + gist_extension
< }]

    files = [{:input => input, :extension => gist_extension}]

$ exec $SHELL

$ gist -d'issue-101-type-option-not-working-from-stdin gist binary' test.txt
https://gist.github.com/3183292

[simeonwillbanks]

Here is the binary for review.

https://gist.github.com/3183335