* Add initial support for getting ChannelMember info of all bridges.
Adds an EventGetChannelMembers event, which gets send every x time to
all bridges. Bridges should respond on this event with a Message
containing ChannelMembers in the EventGetChannelMembers key in the
Extra field.
handleEventGetChannelMembers will handle this Message and sets the
contained ChannelMembers to the Bridge struct.
* Add ChannelMembers support to the slack bridge
When setting wait to true, we wait until the populating isn't in progress anymore.
This is used on startup connections where we really need the initial information
which could take a long time on big servers.
Changes include:
- Refactor of strings into package-wide constants.
- Predeclaration of regexps to be instantiated at package load time.
- Checking of unchecked errors.
- Structural changes:
- Adding verifications to type-casting code.
- Remove unnecessary 'len(X) > 0' checks before iterating over X.
- Remove unnecessary 'else' clause after 'if' with 'return'.
- Unexporting of public fields of Bridge struct.
- Formatting:
- One-field-per-line struct definitions.
