Ensure warnings are displayed when needed

Signed-off-by: emanuele <emanuele45@gmail.com>
Use a unique id to delete temporary attachments

Signed-off-by: emanuele <emanuele45@gmail.com>
Elk needs an hidden field to tell not to delete the temporary attachment

Signed-off-by: emanuele <emanuele45@gmail.com>
The attachID is already unique, so use that instead of another unique string + some variable names consistency

Signed-off-by: emanuele <emanuele45@gmail.com>
Show errors returned by the server while attaching a file

Signed-off-by: emanuele <emanuele45@gmail.com>
Wrong variable

Signed-off-by: emanuele <emanuele45@gmail.com>
Silence errors is bad, though check if a file exists just to try to delete it is a bit of pointless

Signed-off-by: emanuele <emanuele45@gmail.com>
Remove some @ (ob_start)

Signed-off-by: emanuele <emanuele45@gmail.com>
Add some @ back (ob_end_clean)

Signed-off-by: emanuele <emanuele45@gmail.com>
Merge pull request #1582 from emanuele45/fixes

Some attachments stuff