version bump 0.7.8: docs, defaults, details

- browser shim updated (h/t @wintersm for discovering this)
- smart tag ignores (h/t @lostinplace)
- sheet_to_row_object_array bugfix (fixes #80, h/t @ChrisBurkeBSD)
- README improved
- baltic and vietnamese codepages: updated codepage to 1.3.4
- iOS Numbers can handle inline strings -> disabling SST by default
- avoid Buffer accessors (see https://github.com/joyent/node/issues/7809)
- caching certain hot regexes