1. Add `with_configs` decorator to assign available configs
2. Add `only_full_crosslink` decorator to detect if the configuation can
do full crosslinking
3. Add `context.is_pytest` flag: True if calling via pytest. False if
calling from test generator.
See tests/core/pyspec/README.md for usage description.
This commit:
- refactors config loading to be part of the pyspec package
- updates requirements and main files to use new config loading
- cleans up the build script
- converts the build script to a distutil command
- runs pyspec build as part of build package command
- provides pyspecdev command to get editable spec python files
Hsiao-Wei Wang
protolambda
Danny Ryan