Adding code to allow for input validation to continue if value is empty instead of just being marked as valid if empty.  Required to test for validity of an empty value based on context.
Tests for added Continue If empty functionality.
Adding code to allow for input validation to continue if value is empty instead of just being marked as valid if empty.  Required to test for validity of an empty value based on context.
Tests for added Continue If empty functionality.
Allow to set the filter priority in the config array passed to the factory
Splitting 'continue if empty' functionality into its own interface.  Fixing a failing unit test; test was not providing data for a required input.
Catching up with remote differences.
Revert to previous isRequired behavior for file uploads (fix BC break)
Remove unnecessary test for isRequired check
Merge pull request #4165 from zburnham/validate_empty_with_context

Validate empty with context

Conflicts:
	library/Zend/InputFilter/Factory.php
[#4165] CS fixes

- per php-cs-fixer
[#4165] Remove duplicate methods from InputInterface

- `InputInterface` had a BC break, as it added `setContinueIfEmpty()` and
  `continueIfEmpty()` -- which were technically already defined in
  `EmptyContextInterface`, which `Input` had been modified to implement.
  Removing the methods from `InputInterface` removes the BC break, and fixes an
  issue that appears in 5.3.3 with one class implementing two interfaces that
  define compatible methods.
Merge pull request #4148 from leup/filterspriority

Filters priority setting when populating filters in inputfilter factory and not losing it when merging filter chains
Merge branch 'hotfix/4148' into develop

Forward port #4148
Removed errant merge conflict file