The xml API has a few design choices that might be regarded as unusual.

1. order of fields

The quotation request, <PcbQuotationRequest>, is a flat list of mostly
independent children. However, it is very strict about the order
of those children. Fortunately the order matches the one in PCBWay_API.xml.
The ruleset seems to be:
  - divide the children into two groups: board-specific and shipping
  - output board first, shipping next
  - nodes within a group must be alphabetically ordered

2. case sensitivity

Every tag name and enum text fields are case sensitive. The parser will
not accept "no" if the enum value is said to be "No".


3. computer readable API spec

The API is at http://api-partner.pcbway.com/xml/PCBWay_Api.xml
