fixes #341 - download exports in Safari
better management of invalid export file
added filesystem space left for DB folder
added number of files and free disk space on dashbaord
changed version number
Merge branch 'space_left_on_console' into 0.8.1
username is now case insensitive
buttons in table now are btn-mini
fixes #348 When a collection is added via script, the console does not show it
fixes #350 - Exception when a big text file is uploaded