* proxy: add option to set default timestamp for proxy mode, fixes#452
- set via flag --proxy-default-timestamp or config 'proxy_options.default_timestamp'
- can be iso date or all-digit timestamp
- overridable via accept-datetime header
* docs: update docs for proxy timestamp
- add docs on memento support in proxy mode
* update-version: script can update version only, commit with 'update-version.sh commit'
* indexer post append: remove 'WB_wombat_' from POST query, could have been added in previous versions of pywb!
README: update features list, contributing section, fix typos
docs: update features list, fix wording, add more links to other sections, fix typos
renaming: change 'ikreymer/pywb' -> 'webrecorder/pywb', add Rhizome to copyright statement
Dockerfile: remove deprecated MAINTAINER, add 'ARG PYTHON' to support custom base python image
* docs and version update:
- add docs for compatibility features
- add docs for memento
- updat rewriter docs
- bump version to 2.0.0, update README, and changelist