dplyr verb support

[shah-in-boots]

One day (future problem) to add {dplyr} support for specific verbs and the use of tidyselect methods for evaluation.

• filter: could filter terms by criteria (e.g. role == "exposure")
• select: pull out terms by name directly from a list

[shah-in-boots]

When using tbl_reconstruct() the term attributes from strata are inappropriately being pulled forward

[shah-in-boots]

can we use reconstruct methods in the cast and ptype methods?