Don't pass null values in forms

Related to #2513
correct @since inline docs on new audio/video functions
Merge pull request #2522 from pods-framework/feature/2521

Correct @since inline docs on new audio/video functions
up "tested up to" to 2.5
Update WP required version in init.php to 3.8 #2525
inline docs for "pods_pods_fields" filter #2502
Merge pull request #2526 from pods-framework/feature/2525

Update WP required version in init.php to 3.8 #2525
Make sure title is hidden if there is text
Fix for notice

$field_found doesn't need to be reset for each field, since it's a whole form thing
Merge pull request #2529 from pods-framework/feature/2528

Make sure title is hidden if there is text
Merge pull request #2531 from pods-framework/feature/2513

Don't pass null values in forms
Change variable and remove anonymous function
Merge pull request #2530 from pods-framework/feature/2527-noticeinmeta

Fix for notice
Inline docs for pods_pods_field_related_output_type filter #2502
Inline docs for pods_pods_field_ filter #2502
Inline docs for pods_pods_field #2502
Inline docs for pods_pods_fetch #2502
inline docs for "pods_pods_total_found" #2502
Inline docs for "pods_pods_filters" #2502
pods_access used with AND always returns FALSE

Fixes #2536