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>

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

From the documentation:

gmpy2 is a C-coded Python extension module that supports multiple-precision
arithmetic. gmpy2 is the successor to the original gmpy module. The gmpy module
only supported the GMP multiple-precision library. gmpy2 adds support for the
MPFR (correctly rounded real floating-point arithmetic) and MPC (correctly
rounded complex floating-point arithmetic) libraries. gmpy2 also updates the
API and naming conventions to be more consistent and support the additional
functionality.

Signed-off-by: Jeffery To <jeffery.to@gmail.com>