Add support for custom taxonomies in [downloads] shortcode

[d9media]

Hey guys, I would like to propose a patch for adding support for custom taxonomies in [downloads]-Shortcodes. We use additional taxonomies such as Genre, Color, etc. so I jumped into the coded and made a few adjustments:

1. automatically detect all custom taxonomies:

   Array
   (
   [download_category] => 
   [download_tag] => 
   [genre] => 
   [instruments] => 
   [package] => 
   )

2. if any of these are present in our atts, use it:

   
   Array
   (
   [category] => 
   [exclude_category] => 
   [tags] => 
   [exclude_tags] => 
   [author] => 
   [relation] => OR
   [number] => 12
   [price] => no
   [excerpt] => no
   [full_content] => no
   [buy_button] => no
   [columns] => 2
   [thumbnails] => true
   [orderby] => post_date
   [order] => DESC
   [ids] => 
   [pagination] => true
   [download_category] => 
   [download_tag] => 
   [genre] => 
   [instruments] => 
   [package] => 38
   )

Array ( [package] => 38 )

3. condense the part where tags/categories are queried into a more general approach

The code is working good so far, but I would be very interested what you think about my solution. I think this will be a real benefit.

could we also rewrite this function with a custom plug-in?

[Proposed_patch_to_add_support_for_custom_taxonomies_in_shortcodes.patch.txt](https://github.com/easydigitaldownloads/easy-digital-downloads/files/1391621/Proposed_patch_to_add_support_for_custom_taxonomies_in_shortcodes.patch.txt)

[cklosowski]

@d9media Is it possible for you to submit a pull request with this patch so it can be easily tested by our team without the need to apply patches?

[d9media]

Hey @cklosowski, I personally use SVN so this might take a few minutes but I'll try my best.

[cklosowski]

ok no worries. Much appreciated. If not, let me know and I'll see if I can get the patch to apply cleanly into a PR.

[d9media]

@cklosowski, can you see my pull request? I hope it'll be helpful!

[cklosowski]

@d9media yep, I can see it. We'll have a look at it.

[d9media]

I changed the patch so it passes all checks, can you give feedback?