src: Centralize version number

As of this commit, the library's version number is defined in
src/version.hpp, and is propagated to waf/sphinx/doxygen.

Change-Id: I6513cc5a15f2c2afa7cf33844e85d199630fe559
Fixes: #1464
diff --git a/.waf-tools/sphinx_build.py b/.waf-tools/sphinx_build.py
index 32fd78a..bd3905b 100644
--- a/.waf-tools/sphinx_build.py
+++ b/.waf-tools/sphinx_build.py
@@ -8,7 +8,7 @@
 
 class sphinx_build(Task.Task):
     color = 'BLUE'
-    run_str = '${SPHINX_BUILD} -q -b ${BUILDERNAME} -d ${DOCTREEDIR} ${SRCDIR} ${OUTDIR}'
+    run_str = '${SPHINX_BUILD} -D ${VERSION} -D ${RELEASE} -q -b ${BUILDERNAME} -d ${DOCTREEDIR} ${SRCDIR} ${OUTDIR}'
 
     def __str__(self):
         env = self.env
@@ -53,6 +53,8 @@
     task.env['SRCDIR'] = srcdir
     task.env['DOCTREEDIR'] = doctreedir
     task.env['OUTDIR'] = outdir.abspath()
+    task.env['VERSION'] = "version=%s" % self.VERSION
+    task.env['RELEASE'] = "release=%s" % self.VERSION
 
     import imp
     confData = imp.load_source('sphinx_conf', conf.abspath())