Fixes to Spree::TaxCloud#destination_address

* Refer to ::TaxCloud::Address rather than TaxCloud::Address
* taxcloud_usps_user_id.present? because it can be ""
* TaxCloud::Address is initialized with lowercase symbols
Merge pull request #18 from freerunningtechnologies/destination_address

Fixes to Spree::TaxCloud#destination_address
Explicitly call with Spree namespace.
Fixes to Spree::TaxCloud#destination_address

* Refer to ::TaxCloud::Address rather than TaxCloud::Address
* taxcloud_usps_user_id.present? because it can be ""
* TaxCloud::Address is initialized with lowercase symbols
Only calculate eligible adjustments.
Merge pull request #21 from rterbush/eligible-adjustments

Eligible adjustments
Fix removing items from cart when tax adjustment exists.
Fix removing items from cart when tax adjustment exists.
Merge pull request #29 from jdutil/master

Fix removing cart items.
Merge pull request #30 from jdutil/2-0-stable

Fix removing items from cart when tax adjustment exists.
Add line item association.
TaxCloud Savon SOAP client should be a class variable to avoid fetching WSDL file every time we make a new Lookup or Capture call
TaxCloud Savon SOAP client should be a class variable to avoid fetching WSDL file every time we make a new Lookup or Capture call
don't update adjustments for meaningless tax changes
don't update adjustments for meaningless tax changes
Fix precision, scale of decimal columns

The columns were originally created with precision=8 scale=5, which does
not allow prices greater than 999.

This changes
* price to the same as line_item_price (precision=8 scale=2)
* ship_total to the same as adjustment (precision=10 scale=2)
* amount to precision=13 scale=5, which can fit the maximum allowable
  amount of either column at 5 decimal places of precision.
Merge pull request #34 from freerunningtechnologies/column_scale_fix

Fix precision, scale of decimal columns on cart_item
Merge pull request #31 from jdutil/prelaunch

Add line item association.
Merge pull request #32 from dotandbo/2-0-stable

Prevent SOAP client from re-fetching WSDL file from network for every request
cosmetic fix