fixed bug with inventory snapshot chart under Stock Card > Snapshot tab
minor ui improvement to the Stock Card > Consumption tab
OB-3213 Allow user to download purchase order as CSV
OB-3153 Purchase order items should always be sorted in the order entered
minor ui enhancements to product summary buttons and substitutions tab
removed reference to pih.org email address
bumped app version to 0.6.7 (this commit should be used for version tag as the previous one was premature)