Resize attachments all 2.0

Resize attachments all v2.0 changes:

Now supports resize for all content types. Now supports abstracted file system.

Resize attachments all v1.9 changes:

Deleted unused Options page.

Resize attachments all v1.8 changes:

Compatible XF 2.x versions: 2.3

Resize attachments all v1.7 changes:

Now excludes GIF attachments.

Resize attachments all v1.6 changes:

The Limit set in the options page will limit the number of posts to process.

Resize attachments all v1.5 changes:

Changed options page defaults maximum width and height to 2500.

Resize attachments all v1.4 changes:

Added note to indicate the add-on will only resize attachments in thread posts.

Resize attachments all v1.3 changes:

Improved corrupt image error handling.

Resize attachments all v1.2 changes:

Fixed issue dealing with internal_data file missing in file directory.

Resize attachments all v1.1 changes:

Fixed issue dealing with internal_data file missing in file directory.