Update version in dox

We should automate this, but for now we can at least update:

    make -f dev.makefile update-version
    make -f dev.makefile dox
    # Then, go to jsoncpp-doc repo, add, and push.

* https://github.com/open-source-parsers/jsoncpp-docs/issues/2

.gitignore

@@ -52,3 +52,6 @@ compile_commands.json
 
 # DS_Store
 .DS_Store
+
+# temps
+/version

dev.makefile

@@ -1,9 +1,11 @@
 # This is only for jsoncpp developers/contributors.
 # We use this to sign releases, generate documentation, etc.
-VER?=$(shell cat version.txt)
+VER?=$(shell cat version)
 
 default:
 	@echo "VER=${VER}"
+update-version:
+	perl get_version.pl meson.build >| version
 sign: jsoncpp-${VER}.tar.gz
 	gpg --armor --detach-sign $<
 	gpg --verify $<.asc

get_version.pl

@@ -0,0 +1,5 @@
+while (<>) {
+	if (/version : '(.+)',/) {
+		print "$1";
+	}
+}