fix Makefile chmod (644)
replace MD5SUM with HASH
add PKG_MIRROR_HASH when PKG_SOURCE_PROTO:=git

(PKG_SOURCE_PROTO:=svn tarballs are not reproducible for now)

Signed-off-by: Etienne Champetier <champetier.etienne@gmail.com>

I admit this may be be a bit aggressive, but the lang
folder is getting cluttered/filled up with Python, PHP, Perl,
Ruby, etc. packages.

Makes sense to try to group them into per-lang folders.

I took the Pythons.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

Update several dependencies, as well:

* django-compressor -> 2.1.1
* django-constance -> 1.3.4
* django-restframework -> 3.5.4
* django-statici18n -> 1.3.0
* django -> 1.8.17
* openpyxl -> 2.4.2
* python-dateutil -> 2.6.0
* python-urllib3 -> 1.20

Signed-off-by: Gergely Kiss <mail.gery@gmail.com>

Signed-off-by: Gergely Kiss <mail.gery@gmail.com>