os400: build cli manual.

Use PASE perl to run manual generation scripts.

As PASE perl is not aware of all possible input file encoding, convert
all files to UTF-8 upon build sta

os400: build cli manual.

Use PASE perl to run manual generation scripts.

As PASE perl is not aware of all possible input file encoding, convert
all files to UTF-8 upon build start (this might be lengthy).

OS/400 terminal emulation may only offer 76 columns, thus a new -c
parameter has been added to the managen program, defining the allowed
width.

If perl is not available, omit generation and disable online manual.

Closes #14289

show more ...