update version to 3.4.2

update version number

improved comment on msvc
fixed test_method_memory for python 3

updated readme wording

backport memory leak fix for caught exceptions

Change-Id: Ifb5e4264cc2dbb4f7384a0368a8c42ac103880f4

Updated README

fix ninia#1 by shipping a list of jvm classes with jep

getting a list of classes in the runtime is really awful.