handle neo4j errors on flush

fix issue when a neo4j exception is thrown during a tx and not report…

…ed back to user

Merge branch 'master' of github.com:graphaware/neo4j-php-client

fix last change in bolt

updated composer to require ext-mbstring and ext-bcmath, update READM…

…E to specify 4.0 version

added possibility to pass extra curl options

Merge pull request graphaware#49 from PandawanTechnology/port-fix

Refactored default bolt port

Merge pull request graphaware#46 from teqneers/issue45

fixes issue #45: use RecordView::value() to access values

added preflights to Stack

updated chnagelog