* make slate v0 the default for regular sends
* add block_header_version to slate
* update doc tests for latest grin version
* rustfmt
* HACF if HF height detected
* rustfmt
* move api deser types into separate types mod
* rustfmt
* missing types file
* make all exports from libwallet more explicit
* rustfmt
* add version check function to foreign api
* rustfmt
* change check_version return value to result, for consistency