0.5.4

• add TonConnect support (thanks https://github.com/fanfq for the initial code example)
• add getPublickey() to Tonlib;
• add isWallet to Address to detect offline if an address is a wallet contract.
• fix pruned cell serialization (thanks Nikita https://t.me/oyiiyo for the report and bug examples)
• CellBuilder can now specify cell type via .cellType(CellType type) (avoid using new Cell() directly)
• fix VmStackValueInt de/serialization;
• fix issue #43
• reworked VmStack, VmStackValue, VmControlData and VmStackValueInt se/deserialization;
• CellSlice.preloadUint now returns 0 instead of error if too many bits requested.
• add more hashmap de/serialization tests;
• add getKeyByIndex() and getValueByIndex in TonHashMaps;
• add Utils.calculateMethodId("method_name") to calculate methodId for run_method in Tonlib.