New key HY_PKG_LOCATION for query
cosmetic: put HY_PKG_LOCATION into the lists alphabetically.

(where still possible)
subject: best shot at 'some-lib-devel' is not that EVR is 'lib-devel'.

This fully shows that the "best guess" parse and "best guess with known names"
parse should not follow the same order of tested parses. But since nobody uses
the simple best guess yet (i.e. no asking the sack if he knows the name), the
patch optimizes for the latter case. The form order will have to split between
the two later.

Resolves: RhBug:903687
sack_knows() does case-insensitive matching too (pricey yet needed).

Make Subject use the new flag.
py: Query.filter() returns instance of the same type as the original query.

Useful when Query is subclassed.
allow filtering by requires with reldeps. (RhBug:908372)
support filtering by 'obsoletes' and 'conflicts' reldeps. (RhBug:908372)

Includes a fix for memory leak from c5c375f and python bindings.
hy_query_filter_requires() internally converts to a reldep.

Allows me to simplify compute() a bit and remove filter_requires_str().
cosmetic: some python were are not listed in alphabetical order.

This is not as much an OCD-urge as to make it clear where to add new ones later.
Add pkg.conflicts and pkg.provides. (RhBug:908406)
python: reldep_repr() outputs a valid number.

Not a non-recognized format string.
Selector: allow constraining by version only (without the release).
New version: 0.3.7
New build: 0.3.7-2
Forms recognized by ``Subject`` are no longer an instance-scope setting. (RhBug:903687)

Also see a53a6b1 that foreshadowed this change.
sack: allow specifying a different rootdir (AKA "installroot")
doc: added the rootdir parameter to hy_sack_create().
py: expose Subject.pattern
New version: 0.3.8
New build: 0.3.8-1