Add a HY_VERSION_CHECK macro
Set required python version to 2
Fix three trivial comment mis-spellings
add hy_package_get_files.

Introduces new helper type HyStringArray.
py: bindings for package.files.
Install stringarray.h so client programs can use hy_stringarray_free()
py: simplify exception throwing in load_system_repo().
tests: test_get_files(): test against a package with files outside /usr/bin and /etc.
Add API to get and set userdata on a HyPackage instance

Resolves: RhBug:977401

We need to do this as typically in users of the API we are passing around arrays
of packages, and we need to be able to add additional data to them. For instance,
we might want to add the location of the .rpm file of the to-be-installed-package
as it's downloaded in librepo, and retrieved before the package is added to an
rpm transaction.

Adding this data means we do not need a package+key metadata dictionary or any
kind of wrapper object around HyPackage when using hawkey in C programs.
trivial: clang doesn't let us use 0xdeadbeef as a pointer without casting
Add the HySack pointer in the HyPackage structure if available

This allows us to call sack_make_provides_ready() in the future from the package
instance.
New version: 0.3.14
build: 0.3.14-1
py: fix memory leak in sack-py.c:new_package
New version: 0.3.15
build: 0.3.15-1
Do not count updates when counting the number of packages in a sack

Updates in a sack are actually solvables in libsolv, so when we add support for
updateinfo we want to ignore these. Also, we can't assume that nsolvables does
not have holes, so the (nsolvables-2) logic wasn't correct either.
Add updateinfo support to hawkey, using the existing parser in libsolv
Add methods to get details about package updates
Fix a tiny memory leak introduced in 68ebca4a80aec636d30a9fd4fb9aa2d9bf9a8eca