Merge pull request #3148 from jedwards4b/pio2_update

Pio2 update

Update to the latest pio2 development version 2.4.4, set pio2 as default (thought I had already done this)

Test suite: scripts_regression_tests.py
Test baseline:
Test namelist changes:
Test status: bit for bit
Fixes

User interface changes?:

Update gh-pages html (Y/N)?:

Code review: