python: Build the build headers with setup.py.

This allows downstream users to install this python module with pip as
well as allowing people to declare it as a dependency in their setup.py.

Signed-off-by: Damir Jelić <poljar@termina.org.uk>

python/Makefile

@@ -12,10 +12,12 @@ include/olm/olm.h: $(OLM_HEADERS)
 include/olm/pk.h: include/olm/olm.h ../include/olm/pk.h
 	$(CPP) -I dummy -I ../include ../include/olm/pk.h -o include/olm/pk.h
 
-olm-python2: include/olm/olm.h include/olm/pk.h
+headers: include/olm/olm.h include/olm/pk.h
+
+olm-python2: headers
 	DEVELOP=$(DEVELOP) python2 setup.py build
 
-olm-python3: include/olm/olm.h include/olm/pk.h
+olm-python3: headers
 	DEVELOP=$(DEVELOP) python3 setup.py build
 
 install: install-python2 install-python3

python/olm_build.py

@@ -18,6 +18,7 @@
 from __future__ import unicode_literals
 
 import os
+import subprocess
 
 from cffi import FFI
 
@@ -32,6 +33,8 @@ link_args = ["-L../build"]
 if DEVELOP and DEVELOP.lower() in ["yes", "true", "1"]:
     link_args.append('-Wl,-rpath=../build')
 
+headers_build = subprocess.Popen("make headers", shell=True)
+headers_build.wait()
 
 ffibuilder.set_source(
     "_libolm",