Migrate command-line help generation to C.

Command-line help is now generated at build time so it does not need to be committed. This reduces churn on commits that add configuration and/or update the help.

Since churn is no longer an issue, help.auto.c is bzip2 compressed to save space in the binary.

The Perl config parser (Data.pm) has been moved to doc/lib since the Perl build path is no longer required.

Likewise doc/xml/reference.xml has been moved to src/build/help/help.xml since it is required at build time.

test/code-count/file-type.yaml

@@ -1,20 +1,4 @@
 # File types for source files in the project
-build/lib/pgBackRestBuild/Build.pm:
-  class: build
-  type: perl
-
-build/lib/pgBackRestBuild/Build/Common.pm:
-  class: build
-  type: perl
-
-build/lib/pgBackRestBuild/Config/BuildHelp.pm:
-  class: build
-  type: perl
-
-build/lib/pgBackRestBuild/Config/Data.pm:
-  class: build
-  type: perl
-
 doc/doc.pl:
   class: doc/core
   type: perl
@@ -55,6 +39,10 @@ doc/lib/pgBackRestDoc/Common/String.pm:
   class: doc/core
   type: perl
 
+doc/lib/pgBackRestDoc/Custom/DocConfigData.pm:
+  class: doc/core
+  type: perl
+
 doc/lib/pgBackRestDoc/Custom/DocCustomRelease.pm:
   class: doc/core
   type: perl
@@ -147,10 +135,6 @@ doc/xml/metric.xml:
   class: doc/source
   type: xml
 
-doc/xml/reference.xml:
-  class: doc/source
-  type: xml
-
 doc/xml/release.xml:
   class: doc/source
   type: xml
@@ -251,6 +235,30 @@ src/build/error/render.h:
   class: build
   type: c/h
 
+src/build/help/help.xml:
+  class: build
+  type: make
+
+src/build/help/main.c:
+  class: build
+  type: c
+
+src/build/help/parse.c:
+  class: build
+  type: c
+
+src/build/help/parse.h:
+  class: build
+  type: c/h
+
+src/build/help/render.c:
+  class: build
+  type: c
+
+src/build/help/render.h:
+  class: build
+  type: c/h
+
 src/build/install-sh:
   class: build
   type: make
@@ -407,10 +415,6 @@ src/command/expire/expire.h:
   class: core
   type: c/h
 
-src/command/help/help.auto.c:
-  class: core/auto
-  type: c
-
 src/command/help/help.c:
   class: core
   type: c
@@ -2067,6 +2071,10 @@ test/src/module/build/errorTest.c:
   class: test/module
   type: c
 
+test/src/module/build/helpTest.c:
+  class: test/module
+  type: c
+
 test/src/module/command/archiveCommonTest.c:
   class: test/module
   type: c