add script to get version description

scripts/git-version.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+D=`date +%Y%m%d-%H%M`
+TAG=`git describe --dirty --tags --match 'v[0-9]*' --always | sed -e 's/^v//; s/-dirty/-'"$D/"`
+SUFF=`echo $TAG | sed -e 's/[^-]*//'`
+if [ "X$SUFF" = "X" ] ; then
+  # if no -hash or -dirty, just take the tag
+  echo "$TAG"
+else
+  # otherwise, bump the last number of semver
+  # in semver 0.0.7 > 0.0.7-something (think 0.0.7-rc4)
+  PREF=`echo $TAG | sed -e 's/-.*//; s/\(.*\)\.[0-9]*/\1/'`
+  LAST=`echo $TAG | sed -e 's/-.*//; s/.*\.//'`
+  echo "$PREF.$(($LAST+1))$SUFF"
+fi