Upload progress now works also for second file

- Sent bytes must be reseted before new upload, otherwise "onprogress" event "loaded" value provides sum of uploaded bytes (not just for the current upload, but all of them)
Merge branch 'wp8-loaded' of https://github.com/mhujer/cordova-plugin-file-transfer
CB-6802 Add license
ubuntu: support 'cdvfile' URI
CB-6127 Spanish and French Translations added. Github close #21
CB-6877 Updated version and RELEASENOTES.md for release 0.4.4
CB-6877 Incremented plugin version.
CB-6890: Fix pluginManager access for 4.0.x branch
CB-6781: add the exception text to the error object
CB-6781: Continue previous commit with one new instance (This closes #30)
CB-6781: Update new docs to match AlexNennker's changes in PR30