set_value adjust

[madMatchstick]

Readjusts implementation of set_value() to a previous definition. There was a lot of back and forth with how closely bmi definitions followed the csdms examples. The functionality here was overlooked. Recommend reverting back to something working for the time being.

See discussion linked below for the full details.

Addresses issue #43

Changes

• set_value() functions properly via use of internal_array again.

Testing

• At glance, standalone results are producing more reasonable discharge.

[hellkite500]

This is moving the right direction, further refactoring can clean up the implementation, but at least now, set_value is actually modifying data the model uses to make predicitons.