squash! core/commands: Save 'get' output to disk

core/commands: get: Fixed PostRun signature

Refactors for Gateway Server

now, eventlogger works wherever the fsrepo is used

corerepo package name provides sufficient context (even if renamed by
caller)

@jbenet @whyrusleeping

was the 1<<16 intentional? replaced the raw methods with wrappers.

remove prefix logger

Progress Bars

dht query command

Miscellaneous Changes

ipfswatch