[TYPO3-core] RFC #9402: Create a common_locallang-file

[Christopher]

I thought about this problem for a while now:

The question is:
Is a label a "common" label, if it is used at least an exact number of times 
in the core? For example at least for 10 times in the core?

Some parts of the core are not yet translated using xml-files, so that they 
are not taken into account (or do YOU want to look through the whole code?). 
So only looking at the translations of the core is not a reliable way to 
determine, if a label is "common".

Additionally we should also keep in mind, which labels are important for 
extensions.
Here the point is, that there are many extensions which have not yet been 
made translatable (but maybe they will be in future times), so that we 
cannot include reliable numbers for them.

So we always have two things to consider:
On the one hand we really know what IS important (looking at the translated 
parts of the core and looking at the translated extensions).
On the other hand we have to "guess" what there still is to come.

That is why I think that determining one_exact_value of occurences is not 
the right way to handle this problem.

I propose we should rather do a brainstorming on what we think is important 
for the core AND for extensions and then add that to the list we have.
Let's take one week for that.
Then we use the result as common-label-file.

Christopher