* document: `zip_source_write()`: length can't be > `ZIP_INT64_MAX`
* document: `ZIP_SOURCE_CLOSE` implementation can't return error
* keep error codes in man pages in sync
* document: `zip_source_write()`: length can't be > `ZIP_INT64_MAX`
* document: `ZIP_SOURCE_CLOSE` implementation can't return error
* keep error codes in man pages in sync