fix #1712. Number of occurrences was not handled correctly
Fix #1059. make check on new context case insensitive

entering "home" with existing context "Home" will not show a confirmation dialog 
anymore.
add attachment model and add paperclip
change message gateway to save received email as attachment to the todo
wire up downloading attachments from todo partial
ignore attachments in git repo
remove setting utf-8 on every request

this encoding stuff should be handled better with recent versions of rails and ruby
make attachments accesible from user model and fix cleaning up attachment on destroy
refactor adding attachments in message_gateway

and remove gsub magic with correct tempfile parameter
fix failing tests

* tests failed on a local changes site.yml
* somehow universal_newline leaves \r, so bring back gsub to remove them
set permissions on attachments so that users in same group can handle the attachments

if you run MessageGateway under user mail and Tracks under user apache, you cannot 
delete attachments from the web ui since the default permissions is read-only. To
delete an attachment, you need w permission on the directory containing the 
attachment