README: Add hints on using multiple Firefox profiles

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Clean up copyrights

ocproxy.c is 100% original code, so attribute it to David and myself
instead of SICS.  Make it clear that SICS owns the copyright on lwip/*
and contrib/* (these files are all taken as-is from their repo).

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
ppa: Update Debian files

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>