Docs+Packaging: Convert our man pages to Asciidoctor.

Convert doc/*.pod to Asciidoctor. This:

* Means we use the same markup for our man pages, the guides, and
  release notes.
* Lets us add versions to our man pages.
* Gives us more formatting options, e.g. AsciiDoc supports `commands`,
  nested lists and makes it easy to include version information. The
  manpage backend doesn't seem to support tables very well,
  unfortunately.

Convert our CMake configuration to produce *roff and html man pages
using Asciidoctor. Add a "manarg" block macro which makes our synopses
wrap correctly.

Similar to the release notes, guides, and FAQ, if Asciidoctor isn't
found the man pages won't be generated or installed.

Move Asciidoctor to the list of package build dependencies in various
places.

This commit includes the conversion script (pod2adoc.py), which will be
removed later.

Line count sanity check:

Man page         .pod .adoc
androiddump       260  280
asn2deb            93  105
capinfos          401  471
captype            54   55
ciscodump         241  269
dftest             42   42
dpauxmon          153  169
dumpcap           464  534
editcap           528  583
etwdump           136  156
extcap            157  181
idl2deb            91  103
idl2wrs           120  100
mergecap          206  207
mmdbresolve        75   75
randpkt           107  111
randpktdump       158  184
rawshark          558  610
reordercap         76   78
sdjournal         145  157
sshdump           272  302
text2pcap         274  312
tshark           2135 2360
udpdump           133  151
wireshark-filter  486  479
wireshark        2967 3420

2 files changed, 8 insertions, 9 deletions

diff --git a/docbook/wsdg_src/WSDG_chapter_quick_setup.adoc b/docbook/wsdg_src/WSDG_chapter_quick_setup.adoc
index 0c380e7040..e6c8fc70da 100644
--- a/docbook/wsdg_src/WSDG_chapter_quick_setup.adoc
+++ b/docbook/wsdg_src/WSDG_chapter_quick_setup.adoc
@@ -25,8 +25,7 @@ The following must be installed in order to build Wireshark:
 Either make or Ninja can be used to build Wireshark; at least one of
 those must be installed.
 
-To build the Developer's Guide and the User's Guide, Asciidoctor,
-Xsltproc, and DocBook must be installed.
+To build the manual pages, Developer's Guide and User's Guide, Asciidoctor, Xsltproc, and DocBook must be installed.
 
 Some features of Wireshark require additional libraries to be installed.
 
diff --git a/docbook/wsdg_src/WSDG_chapter_tools.adoc b/docbook/wsdg_src/WSDG_chapter_tools.adoc
index d4f4ca3102..3af774f5e1 100644
--- a/docbook/wsdg_src/WSDG_chapter_tools.adoc
+++ b/docbook/wsdg_src/WSDG_chapter_tools.adoc
@@ -452,17 +452,16 @@ Edition, it will include an SDK.
 [[ChToolsDocumentationToolchain]]
 === Documentation Toolchain
 
-Wireshark’s documentation is split across two directories. The `doc`
-directory contains man pages written in Perl’s POD (Plain Old
-Documentation) format. The `docbook` directory contains the User’s
-Guide, Developer’s Guide, and the release notes, which are written in
-Asciidoctor markup.
+Wireshark’s documentation is split across two directories.
+The `doc` directory contains man pages written in Asciidoctor markup.
+The `docbook` directory contains the User’s Guide, Developer’s Guide, and the release notes, which are also written in Asciidoctor markup.
+The split is for historical reasons (described below), and the documentation will likely be consolidated into one directory in the future.
 
 Our various output formats are generated using the following tools.
 Intermediate formats are in _italics_.
 
-Man page roff:: pod2man
-Man page HTML:: pod2html
+Man page roff:: Asciidoctor
+Man page HTML:: Asciidoctor
 
 Guide HTML:: Asciidoctor → _DocBook XML_ → xsltproc + DocBook XSL
 Guide PDF:: Asciidoctor
@@ -478,6 +477,7 @@ The Ruby and Java flavors can be used to build Wireshark’s documentation, but
 
 The guides and release notes were originally written in DocBook (hence the directory name).
 They were later converted to AsciiDoc and then migrated to Asciidoctor.
+The man pages were originally in Perl’s POD (Plain Old Documentation) format and were later converted to Asciidoctor.
 We currently use Asciidoctor’s modern (>= 1.5.0) syntax.
 
 PDF output requires Asciidoctor’s PDF backend.