Fix Windows compatibility

Don't load curses until required. Since it's not available on windows,
importing the module early broke the whole app.

issue #18

toot/app.py

@@ -2,13 +2,19 @@
 from __future__ import unicode_literals
 from __future__ import print_function
 
-import curses
 import webbrowser
 
 from textwrap import wrap
 
+from toot import ConsoleError
 from toot.utils import format_content
 
+# Attempt to load curses, which is not available on windows
+try:
+    import curses
+except ImportError as e:
+    raise ConsoleError("Curses is not available on this platform")
+
 
 class Color:
     @staticmethod

toot/commands.py

@@ -16,7 +16,6 @@ from textwrap import TextWrapper, wrap
 
 from toot import api, config, DEFAULT_INSTANCE, User, App, ConsoleError
 from toot.output import print_out
-from toot.app import TimelineApp
 
 
 def register_app(instance):
@@ -177,6 +176,7 @@ def timeline(app, user, args):
 
 
 def curses(app, user, args):
+    from toot.app import TimelineApp
     generator = api.timeline_generator(app, user)
     TimelineApp(generator).run()
 

toot/console.py

@@ -127,7 +127,7 @@ READ_COMMANDS = [
     ),
     Command(
         name="curses",
-        description="An experimental timeline app.",
+        description="An experimental timeline app (doesn't work on Windows)",
         arguments=[],
         require_auth=True,
     ),