* Replace --create-from-json=file with --json-input, which causes the
regular input to be treated as json.
* Eliminate --to-json
* In --json=2, bring back "objects" and eliminate "objectinfo". Stream
data is never present.
* In --json-output=2, write "qpdf-v2" with "objects" and include
stream data.
This is used to generate a schema for the job json, which can't
contain `)"` because it breaks the R"(...)" syntax in C++. While C++
accepts R"anything(...)anything" to avoid this, as of this writing,
MSVC 2019 doesn't understand that. For now, just avoid it by removing
parentheses from the end of short help.
This is a massive rewrite of the help text and cli.rst section of the
manual. All command-line flags now have their own help and are
specifically index. qpdf --help is completely redone.