support filtering keys

[axos88]

Support the following params:
--include-keys (regex)
--exclude-keys (regex)

By default it includes all keys. If there are any include-exclude params given, they will be executed in chain, and the key will be included based on the output.

For example

redis-dump .... --include-keys foo-.* --exclude-keys foo-bar-.* would include bar, foo-2, but not foo-bar-2

redis-dump .... --exclude-keys .* . --include-keys foo-[0-9]+ would exclude bar, foo-bar-2, but include foo-2