Expose and/or matchers

[kashike]

The and and or matcher implementations are restricted to use by AbstractMatcher, unlike the not (and other matchers in this class) matcher - would it be possible to expose these as Matchers.and(a, b) and Matchers.or(a, b)? This would allow use of these matchers without extending AbstractMatcher for the default implementation, or creating your own matchers.

[cterse]

Its been quite long since this issue was opened. Can I look into this?

[kashike]

@cterse see #1200

[kashike]

The and and or methods in Matcher could be default implemented now that Guice requires Java 8 - is this something that might be considered now, or is this a dead idea?

[sameb]

Yeah, that sounds reasonable.