[BUILD] makefile now detects and uses git to set the version

If git is found during the build process, then it will be used
to set the version, the commit number and the commit date. This
way, it will not be needed anymore to update the code to change
the version. The version is the last tag, and the commit number
is the number of commits since the last tag.
diff --git a/Makefile b/Makefile
index b10fa21..0215a6d 100644
--- a/Makefile
+++ b/Makefile
@@ -1,12 +1,7 @@
 # This makefile supports different OS and CPU setups.
 # You should use it this way :
-#   make TARGET=os CPU=cpu
+#   make TARGET=os CPU=cpu REGEX=lib
 
-# Version of last tag
-VERSION := 1.3.3
-# number of changes since last tag
-SUBVERS := -34
-VERDATE := 2006/12/22
 
 # Select target OS. TARGET must match a system for which COPTS and LIBS are
 # correctly defined below.
@@ -99,6 +94,21 @@
 # - use -DCONFIG_HAP_CTTPROXY to enable full transparent proxy support
 DEFINE = -DTPROXY
 
+# Now let's determine the version, sub-version and release date.
+# If we're in the GIT tree, we can use the last commit's version and date.
+VERSION := $(shell [ -d .git/. ] && ref=$$(git-describe --tags 2>/dev/null) && ref=$${ref%-g*} && echo "$${ref\#v}" )
+
+ifneq ($(VERSION),)
+# OK git is there and works.
+SUBVERS := $(shell comms=$$(git-log --no-merges v$(VERSION).. 2>/dev/null |grep -c ^commit ); [ $$comms -gt 0 ] && echo "-$$comms" )
+VERDATE := $(shell date +%Y/%m/%d -d "$$(git-log HEAD^.. 2>/dev/null | grep ^Date: | cut -f2- -d: | cut -f1 -d+)" )
+else
+# Otherwise, use the hard-coded version of last tag, number of changes
+# since last tag, and release date.
+VERSION := 1.3.3
+SUBVERS := -36
+VERDATE := 2006/12/23
+endif
 
 #### build options
 
@@ -184,7 +194,8 @@
 clean:
 	rm -f *.[oas] src/*.[oas] core haproxy test
 	for dir in . src include/* doc; do rm -f $$dir/*~ $$dir/*.rej;done
-	rm -f haproxy-$(VERSION).tar.gz haproxy-$(VERSION) nohup.out gmon.out
+	rm -f haproxy-$(VERSION).tar.gz haproxy-$(VERSION)$(SUBVERS).tar.gz
+	rm -f haproxy-$(VERSION) nohup.out gmon.out
 
 tar:	clean
 	ln -s . haproxy-$(VERSION)
@@ -195,6 +206,4 @@
 	rm -f haproxy-$(VERSION)
 
 git-tar: clean
-	ref=$$(git-describe --tags); ref=$${ref%-g*}; ver=$${ref#v};\
-	comms=$$(git-log $$ref..|grep -c ^commit); \
-	git-tar-tree HEAD haproxy-$(VERSION) | gzip -9 > haproxy-$$ver-$$comms.tar.gz
+	git-tar-tree HEAD haproxy-$(VERSION) | gzip -9 > haproxy-$(VERSION)$(SUBVERS).tar.gz