This commit adds a TOML configuration option to swarm. It reuses
the TOML configuration structure used in geth with swarm
customized items.
The commit:
* Adds a "dumpconfig" command to the swarm executable which
allows printing the (default) configuration to stdout, which
then can be redirected to a file in order to customize it.
* Adds a "--config <file>" option to the swarm executable which will
allow to load a configuration file in TOML format from the
specified location in order to initialize the Swarm node The
override priorities are like follows: environment variables
override command line arguments override config file override
default config.
This change imports the Swarm protocol codebase. Compared to the 'swarm'
branch, a few mostly cosmetic changes had to be made:
* The various redundant log message prefixes are gone.
* All files now have LGPLv3 license headers.
* Minor code changes were needed to please go vet and make the tests
pass on Windows.
* Further changes were required to adapt to the go-ethereum develop
branch and its new Go APIs.
Some code has not (yet) been brought over:
* swarm/cmd/bzzhash: will reappear as cmd/bzzhash later
* swarm/cmd/bzzup.sh: will be reimplemented in cmd/bzzup
* swarm/cmd/makegenesis: will reappear somehow
* swarm/examples/album: will move to a separate repository
* swarm/examples/filemanager: ditto
* swarm/examples/files: will not be merged
* swarm/test/*: will not be merged
* swarm/services/swear: will reappear as contracts/swear when needed
