Details in exceptions from server are lost

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Alter the code for the commit() function in front.py so that it simply reads 
"assert(False)"
2. Perform a commit using a remote repository with the altered code running on 
the server.

What is the expected output? What do you see instead?
The type of the error correctly propagates to the client, but the details are 
lost. The details are also lost on the server side, they are not sent to the 
system log on linux, nor printed to the terminal when running "boar serve". 
This makes it hard to diagnose server-side errors, especially for user reported 
errors. Instead, the stack trace should be logged in a dedicated boar log file 
on the server, and the client should show a message telling the user that a 
server-side error has occured and to look in the log for details.

Please use labels and text to provide additional information.

Original issue reported on code.google.com by ekb...@gmail.com on 12 Dec 2012 at 10:32