version bump 0.7.7: needs more cowbell

- parsexmltag and other hot functions now better optimized for v8
- monomorphic functions (different types -> different funcs)
- more efficient decode_range implementation when source is trusted
- regular expressions cached and simplified without breaking correctness
- more efficient utf8 techniques when available
- XLSX: large functions broken down into sub-functions (e.g. `parse_ws_xml`)
- XLSB: avoid unnecessary binds
- XLSB: assume no exotic codepage exists (no one else tries to write XLSB)
- demo exposes rABS / worker / transferable options
- more tests
- jszip updated to 2.3.0
- SSF updated to 0.8.1
- codepage updated to 1.3.1