[web/staticcontrollers] create a unique temporary file for concat handling
Predictable names means different processes can race against each other.
Let's avoid that and use mkstemp to get a real unique temporary file,
and atomically rename it when we're done.
Closes #3524182
CSS Coding Standards
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(Draft, to be continued)
:Naming: camelCase
Indentation rules
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- 2 espaces avant les propriétés
- pas d'espace avant les ":", un espace après
- 1 seul espace entre les différentes valeurs pour une même propriété
Documentation
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Please keep rules semantically linked grouped together, with a comment about
what they are for.
Recommendation
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- Try to use existing classes rather than introduce new ones
- Keep things as simple as possible while in the framework
- Think about later customization by application
- Avoid introducing a new CSS file for a few lines of CSS, at least while the
framework doesn't include packing functionalities