Remove needless autogen.sh references/invocations

Since the files autogen.sh creates are now controlled, you only have
to run autogen.sh when you modify the source files, not when you
build from a clean checkout.

README-hardening.md

@@ -16,7 +16,6 @@ make
 In qpdf:
 
 ```
-./autogen.sh
 /tmp/htcondor-analyzer/create-db
 CC=/tmp/htcondor-analyzer/cc CXX=/tmp/htcondor-analyzer/cxx ./configure --disable-shared --disable-werror
 # to remove conftest.c

README-maintainer

@@ -228,7 +228,6 @@ OTHER NOTES
 To construct a source distribution from a pristine checkout,
 `make_dist` does the following:
 
-./autogen.sh
 ./configure --enable-doc-maintenance --enable-werror
 make build_manual
 make distclean

README.md

@@ -33,18 +33,7 @@ Please see the [NOTICE](NOTICE.md) file for information on licenses of embedded
 
 # Building from a pristine checkout
 
-When building qpdf from a pristine checkout from version control, documentation and automatically generated files are not present. You may either generate them or obtain them from a released source package, which includes them automatically generated files. If you want to grab just the automatic files, extract a source distribution in a temporary directory, and run `make CLEAN=1 autofiles.zip`. This will create a file called `autofiles.zip`, which can you can extract in a checkout of the source repository. This will enable you to run `./configure` and build normally. This approach is almost certainly required on Windows because of issues running autoconf. This workaround is also described in [README-windows.md](README-windows.md).
+When building qpdf from a pristine checkout from version control, generated documentation files are not present. You may either generate them (by passing `--enable-doc-maintenance` to `./configure` and satisfying the extra build-time dependencies) or obtain them from a released source package, which includes them. If you want to grab just the files that are in the source distribution but not in the repository, extract a source distribution in a temporary directory, and run `make CLEAN=1 distfiles.zip`. This will create a file called `distfiles.zip`, which can you can extract in a checkout of the source repository. This step is optional unless you are running make install and want the html and PDF versions of the documentation to be installed.
-
-For UNIX and UNIX-like systems, you can build the automatically generated files yourself, but you must have some additional tools installed to build from the source repository.  To do this, you should have `autoconf` installed (`automake` is not required). Then run
-
-```
-./autogen.sh
-./configure --enable-doc-maintenance
-make
-make install
-```
-
-If you don't have Apache fop and the docbook stylesheets installed, you won't be able to build documentation.  You can omit `--enable-doc-maintenance` and produce working qpdf software that passes its test suite, but `make install` will not install documentation files.  Depending on your purposes, this may be fine, or you can grab the docs from a source distribution.
 
 # Building from source distribution on UNIX/Linux
 

appimage/build-appimage

@@ -83,7 +83,6 @@ appdir=$here/build/appdir
 rm -rf $here/build
 
 # Prepare build of QPDF from sources:
-./autogen.sh
 ./configure --prefix=/usr --enable-werror \
             --enable-show-failed-test-output \
             --enable-html-doc --enable-pdf-doc "$CUSTOM_CONFIGURE"

make_dist

@@ -107,7 +107,6 @@ if ($version_error)
     die "$whoami: version numbers are not consistent\n";
 }
 
-run("./autogen.sh");
 run("./configure --enable-doc-maintenance --enable-werror");
 run("make -j8 build_manual");
 run("make distclean");