Fixed that non-empty blank strings as custom field values are not properly validated (#16169).

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extra : convert_revision : svn%3Ae93f8b46-1217-0410-a6f0-8f06a7374b81/trunk%4012938
Always load formatter scripts for when the description is read-only on page load (#16161).

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extra : convert_revision : svn%3Ae93f8b46-1217-0410-a6f0-8f06a7374b81/trunk%4012941
Changeset comments set to longtext for handling comments > 64KB with Mysql (#16143).

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extra : convert_revision : svn%3Ae93f8b46-1217-0410-a6f0-8f06a7374b81/trunk%4012944