CB-6212 iOS: fix warnings compiled under arm64 64-bit

-fix one more warning
CB-6385: Specify file plugin dependency version
CB-6422 [windows8] use cordova/exec/proxy
Merge branch 'dev' of https://git-wip-us.apache.org/repos/asf/cordova-plugin-media-capture into dev
CB-6152: Make mediafile compatible with file plugin
CB-6460: Update license headers
CB-6452 Updated version and RELEASENOTES.md for release 0.3.0
CB-6452 Incremented plugin version on dev branch.