bundled itsdangerous, for tails support
make itsdangerous packaged on any wheezy, not just tails
make itsdangerous actually load in any wheezy
move constant_time_compare function into onionshare from itsdangerous, to avoid dependency problem
in Tails, launch separate root process to do root stuff (#96)
import appropriate modules for constant_time_compare to work
in Tails, root stuff is launched in separate process in GUI (#96)