Distribute the git hash for easier identification.

Change-Id: I57084231d0878de15b4b0478122f49e94af563bf

Makefile.am

@@ -187,6 +187,9 @@ noinst_HEADERS = $(wsd_headers) $(shared_headers) $(kit_headers) \
                  test/countloolkits.hpp \
                  test/helpers.hpp
 
+dist-hook:
+	git log -1 --format=%h > $(distdir)/dist_git_hash 2> /dev/null || rm $(distdir)/dist_git_hash
+
 EXTRA_DIST = discovery.xml \
              favicon.ico \
              loolkitconfig.xcu \

configure.ac

@@ -24,7 +24,7 @@ AC_DEFINE_UNQUOTED([LOOLWSD_VERSION],[["$LOOLWSD_VERSION"]],[LibreOffice Online
 
 # try to add a git hash for a version if we're developing
 LOOLWSD_VERSION_HASH="$LOOLWSD_VERSION"
-git_hash=`cd ${srcdir} && git log -1 --format=%h 2> /dev/null`
+git_hash=`cd ${srcdir} && ( cat dist_git_hash 2> /dev/null || git log -1 --format=%h 2> /dev/null )`
 if test "z$git_hash" != "z"; then
    LOOLWSD_VERSION_HASH=$git_hash
 fi