dev-server: rm --offline from usage since it is gone

Change-Id: I0e5b79113fc03e9cd5c232983a7242a0c543a55e
camlibot: run without --staticres --offline since they are gone

Change-Id: I14d696e2f07967719fa82e4782d8a4ed139b411e
dev/update_closure_compiler: new command

Go program that replaces get_closure_compiler from
misc/get_closure.pl

Change-Id: Ic7471c970afbfc65bc14d9ec2401aeb0d1ecd9a1
make.go: generate the zembeds and rename/mv some globals

We're using the tmp/bin/genfileembed built by
make.go to generate from the static resources
(.html,.js etc) the zembeds.*.go files that
will be embedded in the final binary.

This requires mirroring to the build dir all
said static resources.

A further step will be to remove all the zembeds
from the initial source tree (i.e the git repo).

Change-Id: I25a1aa38d0314b3074cdbedfd4422a685da66191
ui: zembeds should belong to package ui, not newui

Change-Id: I5d69e73280051eb8b97f3e082e5cfe285439dac6