More powerful Options scheme

This prepares us for the addon configuration mechanism and gives us a more
flexible way to handle options changes. This changeset should spell the end of
the current anti-pattern in our codebase where we duplicate data out of options
onto the master when mutability is needed. From now on, Options can be the one
source of thruth.

- Change notifications
- Rollback on error

1 files changed, 4 insertions, 0 deletions

diff --git a/mitmproxy/exceptions.py b/mitmproxy/exceptions.py
index 63bd8d3d..282784b6 100644
--- a/mitmproxy/exceptions.py
+++ b/mitmproxy/exceptions.py
@@ -95,3 +95,7 @@ class FlowReadException(ProxyException):
 
 class ControlException(ProxyException):
     pass
+
+
+class OptionsError(Exception):
+    pass