Refactor: minor Code style, qualified import, typed API, more parentheses
code style: asserts
Groovysh: some more default methods to Map completion
GROOVY-6563: groovysh: Patched jline CompletionHandler to allow ANSIfied candidates
GROOVY-6563: groovysh: jansi rendering of reflection completion candidates
- direct class members bold
- navigable Properties magenta
- GroovyDefaultMethods blue
- non-method members sorted to the end of the candidate list
Groovysh: minor fix: allow changing prefix length preference during session

To reproduce:

set meta-completion-prefix-length 1
'x'.fi

should show find...() methods, does not
GROOVY-6622: Groovysh: show static members only in static context
or with sufficient prefix
Merge pull request #354 from tkruse/groovy6563

Refactorings, GROOVY-6563 and GROOVY-6622