test the existence of modules in the main script

electrum

@@ -18,6 +18,19 @@
 
 import re, sys, getpass
 
+try:
+    import ecdsa  
+except:
+    print "python-ecdsa does not seem to be installed. Try 'sudo pip install ecdsa'"
+    sys.exit(1)
+
+try:
+    import aes
+except:
+    print "AES does not seem to be installed. Try 'sudo pip install slowaes'"
+    sys.exit(1)
+
+
 import electrum
 from optparse import OptionParser
 from decimal import Decimal