Breaking changes: Use fine-uploader-wrappers as external wrappers

All wrapper classes were moved to the fine-uploader-wrappers project. Vue Fine Uploader now depends on fine-uploader-wrappers.

Breaking changes:

Traditional, S3, and Azure wrappers must be imported from 'fine-uploader-wrappers'

You must now import the wrapper classes as follows:

Traditional - import FineUploaderTraditional from 'fine-uploader-wrappers'
S3 - import FineUploaderS3 from 'fine-uploader-wrappers/s3'
Azure - import FineUploaderAzure from 'fine-uploader-wrappers/azure'

Components are now at the root of the package

Instead of import Filename from 'vue-fineuploader/components/filename', you would pull in the <filename /> component as import Filename from 'vue-fineuploader/filename'. All components have moved up one level - the 'components' folder is no more.

Also, <dropzone /> is now the default export for this package. It can be imported as import Dropzone from 'vue-fineuploader'.

re: #17