- Was only used to disable registration when LDAP was enabled.
- Caused saved option not to show on settings page causing confusion.
- Extended setting logic where used to take ldap into account instead of
global override.
- Added warning on setting page to show registration enable setting is
not used while ldap is active.
For #1541
Thumbnail generation would sometimes create a file larger than the
original, if the original was already well optimized, therefore making
the thumbnail counter-productive. This change compares the sizes of the
original and the generated thumbnail, and uses the smaller of the two if
the thumbnail does not change the aspect ratio of the image.
Fixes#1751
