Revert "Reverted to ANTLR 4.5, as per issue CompEvol#744."

This reverts commit 8a1f3ad.

update version history CompEvol#716

Don't close formatter in OperatorSchedule since it closes stdout. fixes 

CompEvol#717

Revert "create bigger range of up-down opeartors for clock models/trees 

CompEvol#228" to guarantee backward compatibility for release CompEvol#716

This reverts commit f05ce05.

add check that taxonset is initialised in RandomTree. fixes CompEvol#694

Merge pull request CompEvol#688 from genomescale/patch-1

Normalise statenode strings

remove trailing full stop from log header. fixes CompEvol#659

Merge branch 'master' of github.com:CompEvol/beast2

Merge pull request CompEvol#634 from genomescale/master

Only applies relative species operator weights to saved XML files

ensure log normal distributions imported from nexus are correctly lab…

…elled in BEAUti's prior panel CompEvol#494