Fixes #11

[asbjorn]

This change introduces a new 'external tool' named 'Export to PDF'. Basically a
shell script that calls 'Pandoc' to convert the markdown file to PDF.

Also added a check to verify that we do have Pandoc installed.

[asbjorn]

Anyone have time to review this PR? Does it look ok?

[jpfleury]

Sorry for the delay. I'll try to look at it as soon as possible. Thanks a lot.

[darkdragon-001]

any news on this?

[asbjorn]

It's a pretty straightforward pull request - any showstoppers?

[asbjorn]

@jpfleury: Does the pull request look OK?

[sixtyfive]

@jpfleury You still active on GitHub? If you just lost interest, perhaps you could invite @asbjorn and/or @nilsmde as collaborators so that they could get the plugin working again?

[asbjorn]

I could fork the project and continue there

[sixtyfive]

I for one would be a happy user @asbjorn :-)
Nothing against retext, but it'd be nice to not need two editors anymore...

[darkdragon-001]

@asbjorn @nielsmde I tried to implement all changes from the forks I could find (I did not finish with @R1kk3r 's changes). Further, I started migrating to WebKit2 (#16, branch webkit2), since the old WebKit is no longer supported on many platforms...

I would join, if someone of you starts a fork ;)

[darkdragon-001]

I just want to let you know, that I created a fork: https://github.com/darkdragon-001/gedit-markdown/

Please test the latest release. Pull requests are always welcome!