Update version to 1.0.0

Merge pull request apple#663 from tbkka/swift-4-truncating-init

Change `extendingOrTruncating` to `truncatingIfNeeded`

Merge pull request apple#612 from tbkka/swift-4-linux-compat

Swift 4 linux compat

Set version to 0.9.903

Version = 0.9.902

Version 0.9.901

Merge pull request apple#477 from thomasvl/oneof_cleanup

Oneof cleanup and generation improvements.

Merge pull request apple#391 from tbkka/tbkka-double-formatter-parser

Major speedup of floating-point handling in JSON/Text

Merge pull request apple#340 from thomasvl/expose_unknown_data

Expose UnknownStorage.data as a r/o Data.

Merge pull request apple#211 from tbkka/tbkka-build-changes

Make perf_runner work with Swift 3.1