[CLEANUP] Improve checkboxes in EXT:scheduler

The checkboxes in EXT:scheduler are too big. Change the CSS class to
fix this.

Resolves: #63126
Releases: master
Change-Id: I2fa43cb14fb4c67967208c59703b584dd832b3b8
Reviewed-on: http://review.typo3.org/34440
Reviewed-by: Benjamin Mack <benni@typo3.org>
Tested-by: Benjamin Mack <benni@typo3.org>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
[BUGFIX] Broken layout for tabs in ExtensionManager

Correct the CSS style of the tabs in the ExtensionManager.

Change-Id: I2078575db684cc826138dce50571cb97f0d653a9
Resolves: #62671
Releases: master
Reviewed-on: http://review.typo3.org/34252
Reviewed-by: Felix Kopp <felix-source@phorax.com>
Tested-by: Felix Kopp <felix-source@phorax.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
[TASK] Migrate ViewPageIcon to Sprite Icon

There are still some small places where
sprite icons are not used yet.

One is the link to the view page icon.
The call within document template
is only used twice in the core:
1. DocumentTemplate->getHeader()
2. ElementInformationController

The patch replaces the hard-coded
image tag with a sprite icon.

As this function is hardly used,
you need to know where to test:
- Go to the Info module
=> PageTSconfig
=> ViewTSconfig fieldContent
=> Choose a page in the pagetree which
is not the root page.
On the bottom you see the TSconfig
for each page, with the search
icon and the new icon once
the patch is applied.

Releases: master
Resolves: #63138
Change-Id: I8d2eaf8fe9a6cf8a6664fcaa33223ac72d637795
Reviewed-on: http://review.typo3.org/34464
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
[TASK] Cleanup BackendController.php (part 1)

The backend controller has some leftover
code. First, the main output is moved
to a standalone fluid view.

Additionally, the UserMenu.js is not
needed anymore, as Bootstrap Dropdown
is taking care of its logic.

Some minor code logic cleanup is also
added, as well as a @todo note.

Releases: master
Resolves: #63145
Change-Id: I9323a036a160561a165ede22a3e707bbe4a540ae
Reviewed-on: http://review.typo3.org/34469
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>