Add Arabic

[Mugahedb]

Translation to Arabic is complete.

[Stanly5]

@Mugahedb Thank you so much for your contribution.
During the reviewing, I found 2 sentence is not translated, so I'd like to explain about it. Updating again should be appreciated.

• "Please press button, RaiDrive will be alive."
  When RaiDrive service is stopped,
  
  and then press the icon(red human)
  

• "{0} free of {1} {2}"
  {1} is total volume of storage, {0} is current free space. {2} is not used now. These will be replaced to detected volume.
  For example, if {1} is 5.00GB, and {0} is 4.01GB, then "4.01GB free of 5.00GB"

If you need more information, then please let me know.

[Stanly5]

@Mugahedb
I'd like to share the captured images for reviewing before release test version of translation, even not complete screen. If you find something to be improved or changed, Issuing Pull request again would be greatly appreciated.

[Stanly5]

@Mugahedb
RaiDrive 1.4.0 is released. With your great contribution, translated Arabic is applied on it and also new file can be tested with it.