* basic invoiced tx working
* rustfmt
* teardown
* rustfmt
* rename, new struct for invoice args, begin to add new functions to RPC apis
* rustfmt
* add fns to rpc api
* rustfmt
* owner api functions RPC documentation in place
* rustfmt
* doctests for new invoicing functions
* rustfmt
* test fixes
* update documentation and doctests
* rustfmt
* invoice testing verification of tx log output
* 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
* store receiver's output into the sender's database
* rustfmt
* payment output refresh
* fix the test code in libwallet
* rustfmt
* fix wallet_command_line test
* modify the warning message for self sending
* a bit of unit test according to review comments
* display unknown value for the case of multiple outputs on single receiver, normally it's not the case of this wallet implementation
* rustfmt
* fix merge missing parts
* rustfmt
* use PaymentCommitMapping struct instead of a tuple
* rustfmt
* fix the test
* fix the owner api rpc test
