[BUGFIX] RTE Spellcheck: PHP warning in SpellCheckingController

PHP warning in raised in
SpellCheckingController::fixPersonalDictionaryCharacterSet.
If the file does not exist, there is no need to fix anything.

Releases: master, 6.2
Resolves: #62137
Change-Id: I9b15f5cb016ac9d309fb19ad6230a79b885b16f3
Reviewed-on: http://review.typo3.org/33239
Reviewed-by: Stanislas Rolland <typo3@sjbr.ca>
Tested-by: Stanislas Rolland <typo3@sjbr.ca>
[FEATURE] RTE: Cleanup in SpellCheckingController

Add comments. Clearer Aspell command construction.

Releases: master
Resolves: #62138
Change-Id: Ib553d782bc2602c53540e7a532f14cdd4e62fbb8
Reviewed-on: http://review.typo3.org/33241
Reviewed-by: Stanislas Rolland <typo3@sjbr.ca>
Tested-by: Stanislas Rolland <typo3@sjbr.ca>
[TASK] Improve namings of RadioElement

Resolves: #62034
Releases: master
Change-Id: I894923e9b84109b3b3badff3e94662a41e84d6d0
Reviewed-on: http://review.typo3.org/33165
Reviewed-by: Stefan Froemken <froemken@gmail.com>
Tested-by: Stefan Froemken <froemken@gmail.com>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>
[BUGFIX] Static access to Enumeration constants

To get all available constants for a TYPO3\CMS\Core\Type\Enumeration
an instance of the Enumeration is required. This is changed by
defining the `getConstants` method as static and using
`get_called_class()` instead of `get_class($this)`.

Resolves: #61090
Releases: master,6.2
Change-Id: I45e8241c6f41a23a1748e620c000b6dd59d6f389
Reviewed-on: http://review.typo3.org/32353
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Mathias Brodala <mbrodala@pagemachine.de>
Tested-by: Mathias Brodala <mbrodala@pagemachine.de>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>
[BUGFIX] Fix typo in ChecboxElement

When calling the deprected method getSingleField_typeCheck
a wrong class name is called.
It has to be CheckboxElement instead of ChecboxElement

Resolves: #62149
Releases: master
Change-Id: Ie3db582ea40bb5e55ac4f59ac6c89364304f5723
Reviewed-on: http://review.typo3.org/33249
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
[BUGFIX] Show empty icon in checkbox'ed select field

When a select field has config option renderMode=checkbox, icons
are rendered between checkbox and the label. If no icon is defined,
TYPO3 ought to show an empty icon.
This is broken and a red question mark appears.
This patch fixes the problem so that the empty icon is rendered again.

Change-Id: I2c54695463d98bd7b8bfa66642bd861e7a2ca7a8
Resolves: #62116
Releases: master, 6.2
Reviewed-on: http://review.typo3.org/33220
Reviewed-by: Stefan Froemken <froemken@gmail.com>
Tested-by: Stefan Froemken <froemken@gmail.com>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Reviewed-by: Christian Weiske <christian.weiske@netresearch.de>
Tested-by: Christian Weiske <christian.weiske@netresearch.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>