rework parse errors into diagnostics

add setLogStream

switch to a general logger in source manager, add pConfig rootDir

add pSourceManager::configure, move from frontend

add LICENSE

install ast def file

add install target

switch to pSourceRange only, and fix support for catch nodes so that they contain var nodes

better handling of use/decl in branches

add redecl assertion back in

fix decl use with multiple redeclares

handle global vars properly in usedecl

ignore superglobals in decl/use

finish model and diags for namespace constants

fixes to constdecl