more explicit error messages during common import errors

modules/aum/captcha.py

@@ -20,7 +20,11 @@
 
 import hashlib
 import sys
-import Image
+
+try:
+    import Image
+except ImportError:
+    raise ImportError('Please install python-imaging')
 
 class CaptchaError(Exception): pass
 

modules/freemobile/pages/login.py

@@ -19,7 +19,11 @@
 
 
 import time
-import Image
+
+try:
+    import Image
+except ImportError:
+    raise ImportError('Please install python-imaging')
 
 from weboob.tools.browser import BasePage
 

modules/societegenerale/captcha.py

@@ -19,7 +19,11 @@
 
 
 import hashlib
-import Image
+
+try:
+    import Image
+except ImportError:
+    raise ImportError('Please install python-imaging')
 
 
 class TileError(Exception):

modules/youtube/backend.py

@@ -20,8 +20,12 @@
 
 from __future__ import with_statement
 
+try:
+    import gdata.youtube.service
+except ImportError:
+    raise ImportError("Please install python-gdata")
+
 import datetime
-import gdata.youtube.service
 import re
 import urllib
 

weboob/tools/browser/browser.py

@@ -22,7 +22,12 @@ from __future__ import with_statement
 from copy import copy
 from httplib import BadStatusLine
 from logging import warning
-import mechanize
+
+try:
+    import mechanize
+except ImportError:
+    raise ImportError('Please install python-mechanize')
+
 import os
 import sys
 import re

weboob/tools/captcha/virtkeyboard.py

@@ -19,7 +19,11 @@
 
 
 import hashlib
-import Image
+
+try:
+    import Image
+except ImportError:
+    raise ImportError('Please install python-imaging')
 
 
 class VirtKeyboardError(Exception):

weboob/tools/misc.py

@@ -20,7 +20,11 @@
 
 from __future__ import with_statement
 
-from dateutil import tz
+try:
+    from dateutil import tz
+except ImportError:
+    raise ImportError('Please install python-dateutil')
+
 from logging import warning
 from time import time, sleep
 from tempfile import gettempdir

weboob/tools/newsfeed.py

@@ -18,7 +18,12 @@
 # along with weboob. If not, see <http://www.gnu.org/licenses/>.
 
 import datetime
-import feedparser
+
+try:
+    import feedparser
+except ImportError:
+    raise ImportError('Please install python-feedparser')
+
 if feedparser.__version__ >= '5.0':
     # feedparser >= 5.0 replaces this regexp on sgmllib and mechanize < 2.0
     # fails with malformated webpages.