Merge both config and integer changes from Trunk: these are interlinked.
Merge link fix for integer.
Merge fixes from Trunk.
Merge documentation fixes.

* Use `doc/src/*.css` instead of `doc/html/*.css`.
* Remove wiki and people directories.
* Some documentation fixes.
* Left out `minimal.css` changes and boostbook changes because of clashes.
Merge integer documentation.
Fix logic in cstdint to prefer smaller integers when possible.
Improve PP-logic in integer-traits.
Suppress some compiler warnings.
Merge [68802] from the trunk.
Merge typo fixes from Trunk.
Merge minor integer fixes from Trunk.
Merge changes from trunk:

Fix PDF install rule so that it's explicit and automatically invokes a PDF build when specified on the command line.
So "bjam pdfinstall" will now build and install the PDF to the current directory.
This works around some problems that the previous versions had if the user did not have an FO processor installed (basically Daniel James was unable to build the HTML docs for the distribution if the pdfinstall rule was implicit).