v2.15.2
Remove LZMA support
include: Stop using *Ptr typedefs in public headers
catalog: Fix initialization
Revert "dict: Rework reference counting"
io: Consolidate escaping code
save: Fix handling of catastrophic errors
globals: Also use global state struct if threads are disabled
doc: Remove more comment block headers
valid: Don't add ids when validating entity content
relaxng: Added xmlRelaxNGValidCtxtClearErrors to recover from errors during streaming validation
error: Refactor error reporting
threads: don't force _WIN32_WINNT to Vista if it's set to a higher value
tree: More xmlNodeParseContent cleanup