Extract string and class logic from parse_spec
Check Requirement before Dependency

It's much more likely that an instance of Requirement is passed.
TypeError is appropriate here
Reduce allocations in dependency construction

By always passing around a single, unnested array rather than splatting
and then defensively flattening and compacting things, we can avoid
allocating a bunch of unnecessary arrays. This gives a performance boost
of roughly 4% when enumerating 2500 formulae, and has the side effect of
cleaning up the dependency API.
Avoid extra array allocations
Fix type error in conflict_requirement

Fixes #19636.
netpbm: use max_intall_names

Closes #16944.
xctool: add --HEAD

Closes #19633.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
couchdb 1.3.0

Closes #19112.

Signed-off-by: Misty De Meo <mistydemeo@gmail.com>