[Common] Fix IO_ERR message

FileSystem TCT Test "File_readAsText_with_onerror.html" requires
that the error message can't be null.

code:
  assert_not_equals(error.message, "", "incorrect error message");
[FileSystem] Fix ConvertFrom() base64 decode algorithm

fixed by: Leandro A. F. Pereira
[FileSystem] Add FileStream fstream support

Before this fix, FileStream used FileDescriptor to access its files.
We had some problems dealing with the position attribute, so we
decide to look how tizen deals with it. Tizen uses fstream to handle
the FileStream class, so as we do now.
Merge pull request #225 from ricardotk/wip-filesystem

[FileSystem] Add FileStream fstream support
Bump version to 0.16
WIP
[Bluetooth] Fix not passing a SuccessCallback to stopDiscovery()

When should check if successCallback passed to stopDiscover() exists
(if it exists, its type is already correct) before calling it.
[Bluetooth] Fix sending wrong reply to BluetoothAdapter.stopDiscovery()

The reply id of the call should be cleared after it is handled.
[Bluetooth] Only send the dummy adapter if bluetoothd is not running

If there are chances that bluetoothd is running, it is better that
we wait for we to get the necessary objects, than it is to reply
with the dummy adapter and then update it with the correct information.
[Bluetooth] Ignore the error if the adapter is already enabled

In the tizen case, when the adapter is already up, but we didn't
get all the objects yet and we receive a setPowered() call, we may
try to enable an already enabled adapter, and it will fail.

We convert the error to an POSIX error so the dependence on tizen
headers are contained.
fixup!