Merge pull request #1 from montegoulding/feature/externals_v5

Feature/externals v5
[[ ExternalsApiV5 ]] Fix negative number tokenization.
Merge branch 'feature-externals_api_v5' of https://github.com/runrevmark/livecode into feature-externals_api_v5
[[ ExternalsApiV5 ]] Get notify system working on iOS (Android not yet working).