Connection errors in SongSelect are not handled

See http://support.openlp.org/scp/tickets.php?id=2837

**OpenLP Bug Report**
Version: {'version': '2.1.5', 'build': None, 'full': '2.1.5'}

--- Details of the Exception. ---

Can't log into CCLI Song Select at all, very frustrating

 --- Exception Traceback ---
Traceback (most recent call last):
  File "c:\Python33\lib\urllib\request.py", line 1248, in do_open
  File "c:\Python33\lib\http\client.py", line 1061, in request
  File "c:\Python33\lib\http\client.py", line 1099, in _send_request
  File "c:\Python33\lib\http\client.py", line 1057, in endheaders
  File "c:\Python33\lib\http\client.py", line 902, in _send_output
  File "c:\Python33\lib\http\client.py", line 840, in send
  File "c:\Python33\lib\http\client.py", line 1194, in connect
  File "c:\Python33\lib\socket.py", line 435, in create_connection
  File "c:\Python33\lib\socket.py", line 426, in create_connection
TimeoutError: [WinError 10060] A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "D:\OpenLP_Development\OpenLP_Code\2.1\openlp\plugins\songs\forms\songselectform.py", line 255, in on_login_button_clicked
  File "D:\OpenLP_Development\OpenLP_Code\2.1\openlp\plugins\songs\lib\songselect.py", line 85, in login
  File "c:\Python33\lib\urllib\request.py", line 469, in open
  File "c:\Python33\lib\urllib\request.py", line 487, in _open
  File "c:\Python33\lib\urllib\request.py", line 447, in _call_chain
  File "c:\Python33\lib\urllib\request.py", line 1283, in https_open
  File "c:\Python33\lib\urllib\request.py", line 1251, in do_open
urllib.error.URLError: <urlopen error [WinError 10060] A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond>

--- System information ---
Platform: Windows-8-6.2.9200

--- Library Versions ---
Python: 3.3.2
Qt4: 4.8.5
Phonon: 4.4.0
PyQt4: 4.10.3
QtWebkit: 534.34
SQLAlchemy: 0.9.4
SQLAlchemy Migrate: -
BeautifulSoup: 4.3.2
lxml: 3.2.3
Chardet: 2.2.1
PyEnchant: 1.6.6
Mako: 1.0.0
pyICU: 1.5
pyUNO bridge: -
VLC: -