Provide a new set of functions to create xmlParserInputs. These can be
used for the document entity or from external entity loaders.
- Don't require xmlParserInputBuffer.
- All functions take a base URI.
- All functions take an encoding as string.
- xmlNewInputURL also takes a public ID.
- xmlNewInputMemory takes a size_t.
- Optimization hints for memory buffers.
Improve documentation.
Only call xmlInitParser before allocating a new parser context.
Call xmlCtxtUseOptions as early as possible.