allows multiselect during upload for select applications
Added an api check, since multiselect only works on api level 18+
This commit targets https://github.com/owncloud/android/issues/596
1. allows multiselect during upload for select applications
2. Added an api check, multiselect is only supported on api level 18+
merge
Removes build version magic numbers
Merged with owncloud develop
Merge branch 'develop' of https://github.com/owncloud/android into multi2
Merge pull request #718 from owncloudChalmers/multi2

Multiselect functionalty targeting https://github.com/owncloud/android/issues/596