change how error subclasses are generated

This commit brings back a "package MongoDB::*" statement for every
error subclass so that META generators will find them for indexing,
while still avoiding repetitive "use Moose/namespace:::clean/extends"
lines.
prune devel/dist/weaver from distdir
implement sharded cluster orchestration
rename local orchestration config for better alpha sorting
suppress server startup warnings in local orchestration
add orchestration version ranges and more sharded clusters
add old-style master mode cluster to local orchestration tests
add mixed-version replica set cluster to local orchestration
Merge branch 'orchestrate-shards'