PERF/ENH: Speed up imports
PERF/ENH: Speed up imports

Author: Phillip Cloud <cpcloud@gmail.com>

Closes #1074 from cpcloud/fix-import-perf and squashes the following commits:

fc976e8 [Phillip Cloud] PERF/ENH: Speed up imports

deepfield/ibis,ibis-project/ibis,cloudera/ibis,cloudera/ibis,ibis-project/ibis,cpcloud/ibis,ibis-project/ibis,ibis-project/ibis,cpcloud/ibis,deepfield/ibis,cpcloud/ibis,deepfield/ibis,cpcloud/ibis,deepfield/ibis,cloudera/ibis