OpenSystemsDevelopment / qpdf

Handle various options that were handled in Makefile code.

Files are copied into the build area rather than left in the source
tree, and the test suite looks for them there. Also remove special
case around counting files in the qpdf corpus.

Also update to cmake variable rather than autoconf variable

With cmake, we are customizing the path for each test suite so we can
ensure we get the right qpdf without having to use an environment
variable.

Run compare images tests when QPDF_TEST_COMPARE_IMAGES is set rather
than when QPDF_SKIP_TEST_COMPARE_IMAGES is not set.

It's better to just make it a .hh file to reduce confusion.

Also fix typo in pdf-attach-file example.

Convert loop to use range-based for statement.
Remove unnecessary variables.

Convert loop to use range-based for statement.
Remove unnecessary variables.

Version 1.8 allows QTC::TC to break across lines.

This is so it will fit on one line after a qtest upgrade allows us to
split lines.

This was mainly to get comments about defaults out of constructor
initializer lists where their fragile when a code formatter is being
used.

We have been keeping main's version at the last released version, but
starting now, main's version will always be whatever it would be if
a release were cut from the tip of main.

Some people don't know what CI is, so remove use of that abbreviation
when it doesn't add any value.