Opening a file with a zero sharing mode makes read-only access exclusive
on Windows. Allow read and write sharing so callers can inspect files
that are already open, such as active log files.
Replace all calls to epee::file_io::get_file_size with
boost::filesystem::file_size in order to avoid lossy conversions from
paths to strings, which tend to break filename resolution. This commit
fixes a bug on Windows where the get_info RPC call reported a zero
database size because BlockchainLMBD::get_database_size returned zero.
selsta