TYPO3 Core

With the recent label updates from JoH, Ingo, and others, the CSH doesn't match the actual labels for pages and tt_content very well.

In addition, a lot of the CSH descriptions are outdated and could use a little tweaking for their grammar. This hasn't been a complete rewrite of the CSH but more of a cleanup while fixing the label issues.

Additionally, we want to make these changes as easy as possible on the translators so that the existing CSH continues to work if new translations are not available.

1) Create new CSH files (inside a 4.5 folder) for pages and tt_content so that old TYPO3 versions are not affected.
2) Register these new CSH files using $TYPO3_CONF_VARS']['SYS']['locallangXMLOverride']

When CSH is requested, the hierarchy will look like this....
1) Check for new 4.5 label in the current language
2) Check for old label in the current language
3) Check for new 4.5 label in the default language
4) Check for old label in the default language

In addition to tt_content and pages, there are 2 updates for CSH files that use SysFolder rather than the new Folder label.

(issue imported from #M16988)