Gravity Perks File Upload Pro 1.3.17

Added new gpfup_strip_image_metadata JavaScript filter to control whether or not image metadata/EXIF should be stripped from uploaded images.
Added new gpfup_jpeg_quality JavaScript filter for controlling the JPEG quality used when saving cropped images.

Added support for accessing File Upload Pro JavaScript instance using window.GPFUP_FORMID_FIELDID format. As a result, window.GPFUP was renamed to window.GPFUP_CONSTANTS and window.GPFUP_FORM_FORMID was renamed to window.GPFUP_FORM_INIT_FORMID.
Added gpfup_strings JavaScript filter for customizing localized strings used on the frontend.
Fixed issue where the image preview dimensions would be set to 0 causing the preview to not show if only image extensions are allowed.
Added [gpfup_skip_image_loader](https://gravitywiz.com/documentation/gpfup_skip_image_loader/] JavaScript filter.
Fixed issue where cropping constraints would be applied/enforced even with cropping disabled.

Fixed issue where long filenames were not correctly truncated via styles. (#24)